Method of reducing pulmonary exacerbations in respiratory disease patients

ABSTRACT

Described are methods of reducing pulmonary exacerbations and methods of treating cystic fibrosis, including methods of reducing pulmonary inflammation, comprising administration of an LTA4h inhibitor.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/427,571, filed May 31, 2019, which claims the benefit of U.S.Provisional Application No. 62/678,964 filed May 31, 2018 and U.S.Provisional Application No. 62/702,038 filed Jul. 23, 2018. The entirecontents of the above-referenced applications are incorporated byreference herein.

BACKGROUND OF THE INVENTION

Pulmonary pathology in the cystic fibrosis (CF) lung is characterized byhigh levels of inflammation that leads to pulmonary exacerbations, lungfunction decline and associated morbidity and mortality. Inflammatorylung damage is evident early in life, with increased neutrophil elastasein bronchoalveolar lavage fluid clearly linked to the risk of developingstructural lung damage (including bronchiectasis) at as early as threemonths of age in children with cystic fibrosis [Sly et al., 2013].Inflammation-induced damage can occur even in the absence of detectableinfection [Tirouvanziam et al., 2002; Verhaeghe et al., 2007].Inflammation also persists despite high standards of care and noveltherapies such as cystic fibrosis transmembrane conductance regulator(CFTR) modulators [Rowe et al., 2014]. Chronic inflammation in the CFlung is driven by the persistent recruitment of immune cells,principally neutrophils, into the airways [Downey et al., 2009].Modulation of the inflammatory mediators that drive neutrophil influxmay provide a viable therapeutic pathway to reduce inflammation in thelung [Cantin et al., 2015].

Despite the recognition that treatment of chronic lung inflammation isan unmet need in CF treatment, studies of anti-inflammatory agents haveyielded mixed results. In high doses, the nonsteroidal anti-inflammatorydrug ibuprofen slows lung function decline in patients and improvessurvival in children with CF [Konstan et al., 1995; Konstan et al.,2018, Lands et al. 2007, Lands et al., 2016]. Yet, despite evidence ofefficacy, high dose ibuprofen is infrequently used to treat inflammationin CF due to concerns of gastrointestinal and renal toxicity and theneed for pharmacokinetic-based dosing [Chmiel et al., 2015; Balfour-Lynnet al., 2007]. A clinical trial of the anti-inflammatory, BIIL 284(amelubant), an antagonist of the BLT1 receptor, in patients with stableCF lung disease was terminated early due to an increase in respiratoryserious adverse events characterized by an increased presentation ofsymptoms associated with pulmonary exacerbation [Konstan et al. 2014].This trial has been described as a “cautionary tale” for theadministration of anti-inflammatory compounds in CF due to theirpotential to suppress the inflammatory response and thus increase therisk of infection [Konstan et al. 2014]. Doring et al. (2014) suggesteda mechanism for this increased risk by demonstrating that administrationof BIIL 284 to mice (at doses of 0.3 to 100 mg/kg) significantlydown-regulated Mac-1 (CR3) and reduced the number of neutrophils in thelungs and the airways of P. aeruginosa-infected mice.

The target of BIIL 284, the BLT1 receptor, is the primary receptor forleukotriene B4 (LTB₄). LTB₄ is an immune cell chemoattractant andactivator implicated in the initiation of cytokine and chemokinecascades that amplify and perpetuate inflammation via neutrophilswarming behavior [Lammerman et al., 2013; Afonso, et al. 2012; Sadikand Luster, 2012]. LTB₄ is generated from leukotriene A4 (LTA₄) by theenzyme leukotriene A4 hydrolase (LTA₄-h). LTA₄-h is a monomeric, soluble69 kD zinc metalloenzyme that catalyses two reactions: thestereospecific epoxide hydrolase reaction to convert LTA₄ to leukotrieneB4 (LTB₄) and an aminopeptidase cleavage of small peptide substrates.Inhibition of LTA₄-h has the potential to reduce LTB₄ production, thusreducing neutrophil influx and the release of neutrophil-derived enzymessuch as neutrophil elastase (FIG. 1). [Woolhouse et al., 2002;Tirouvanziam 2006].

LTA₄-h inhibitors have been described, for example, in U.S. Pat. Nos.7,737,145, 9,820,974, and U.S. Patent Application Publication No.20100210630A1, the contents of each of which are incorporated byreference herein. A specific LTA₄-h inhibitor described in these patentpublications is4-{[(1S,4S)-5-({4-[4-oxazol-2-yl-phenoxy]phenyl}methyl)-2,5-diazabicyclo[2.2.1]heptan-2-yl]methyl}benzoicacid (also referred to herein as CTX-4430 and by its InternationalNonproprietary Name, acebilustat). Acebilustat is an oral therapy thatmodulates LTB₄ production and targets inflammatory process in CF [Elbornet al., 2017a]. In two Phase I trials, acebilustat reduced LTB₄production and other inflammatory markers in healthy volunteers andpatients with CF [Elborn et al., 2017a, Elborn et al., 2017b].

There remains a need in the art for safe and effective anti-inflammatorytreatment of cystic fibrosis. It would therefore be advantageous todevelop additional methods of reducing pulmonary inflammation in cysticfibrosis patients and/or prevent or reduce loss of lung function and/orreduce pulmonary exacerbations in CF patients. In addition, consideringthe lack of clear precedent for successfully developing ananti-inflammatory treatment in cystic fibrosis, identifying anappropriate treatment population and/or clinical outcome is alsoimportant.

SUMMARY OF THE INVENTION

The present invention is directed to a method of treating cysticfibrosis and other respiratory diseases, including methods of decreasingpulmonary exacerbations, including reducing the risk of pulmonaryexacerbations and/or reducing the rate (such as the annual or annualizedrate), number or frequency of pulmonary exacerbations, increasing thetime to first pulmonary exacerbation, and/or reducing pulmonaryexacerbations such that the patient does not experience any pulmonaryexacerbations for at least one year (after initiating treatment withacebilustat). In certain embodiments, the methods comprise orallyadministering to cystic fibrosis or other respiratory disease patientsacebilustat at a total daily dose of about 100 mg or less, about 50 mgor less, from about 50 mg to about 100 mg, about 100 mg, or about 50 mg.The methods also include reducing pulmonary inflammation and methods oftreating chronic pulmonary inflammation in a cystic fibrosis patient.

It has been discovered that a major effect of acebilustat treatment isreduction in pulmonary exacerbations, including reducing the rate (forexample, number or frequency) of pulmonary exacerbations and/orincreasing the time to first pulmonary exacerbation. In addition,acebilustat treatment resulted in an increased proportion of patientsthat were exacerbation free (experienced no pulmonary exacerbations)after initiating acebilustat treatment over the course of the 48 weeksof study. It has been discovered that acebilustat treatment has itsgreatest effect in cystic fibrosis patients having a phenotypecharacterized as mild lung disease (e.g., patients having a FEV₁ppgreater than about 65% at the start of treatment or at baseline) ascompared to patients with more severe lung disease. Specifically,anti-inflammatory treatment comprising acebilustat reduced the rate ofpulmonary exacerbations and increased the time to first pulmonaryexacerbation in cystic fibrosis patients of the mild lung diseasephenotype as compared to that in patients treated with placebo or inpatients with moderate or severe lung disease. This effect was observedwhether patients were taking or not taking concomitant treatment withCFTR modulator therapy. Notably, the greatest benefit of acebilustattreatment was observed in patients having the mild lung diseasephenotype and taking CFTR modulator therapy, although a benefit was alsoobserved in patients with mild disease not taking CFTR modulatortherapy. Furthermore, the benefit of acebilustat treatment observed inpatients taking concomitant CFTR modulator therapy was observedregardless of lung disease phenotype, and the effect on pulmonaryexacerbation was greater than that in patients not taking CFTR modulatortherapy in this population with a broader range of disease severity.

Therefore, in certain aspects, invention is directed to a method ofdecreasing pulmonary exacerbations, including reducing the rate (forexample, number or frequency) of pulmonary exacerbations or increasingthe time to first pulmonary exacerbation, in a patient in need thereofcomprising orally administering to the patient acebilustat at a totaldaily dose of about 100 mg or less. The patient in need of treatment canbe a patient suffering from a respiratory condition characterized by theoccurrence of pulmonary exacerbations. Such respiratory conditionsinclude, for example, cystic fibrosis, bronchiectasis, chronicobstructive pulmonary disease, and interstitial lung disease. In certainaspects, the invention includes a method of decreasing pulmonaryexacerbations, including reducing the number or frequency of pulmonaryexacerbations or increasing the time to first pulmonary exacerbation, ina cystic fibrosis patient comprising orally administering to the patientacebilustat at a total daily dose of about 100 mg or less. In certainaspects, the patient, such as a cystic fibrosis patient, does notexperience any pulmonary exacerbations for at least one year afterinitiating oral administration with acebilustat. Acebilustat can also,for example, be administered to the patient, such as a cystic fibrosispatient, at a total daily dose of about 50 mg or less, or about 100 mg,or about 50 mg, about 50 mg to about 100 mg. In yet additional aspects,the total daily dose of acebilustat is 100 mg. In certain aspects, thepatient, such as a cystic fibrosis patient, has a mild lung diseasephenotype, for example, the patient has a FEV₁pp greater than about 65%at baseline, greater than about 68% at baseline, greater than about 70%at baseline (the CF community standard definition of “mild” CF disease),or greater than about 75% at baseline. In yet additional aspects, thepatient, such as a cystic fibrosis patient, has a FEV₁pp greater than orequal to about 65% at baseline, greater than or equal to about 68% atbaseline, or greater than or equal to about 70% at baseline, or greaterthan or equal to about 75% at baseline. In certain aspects, the methodcomprises measuring FEV₁pp in a patient (at baseline or prior toinitiating treatment), for example, by spirometry, and administeringacebilustat (at a total daily dose of about 100 mg or less, as describedherein) to the patient if the patient has an FEV₁pp greater than orequal to about 65%, greater than or equal to about 68%, or greater thanor equal to about 70%, or greater than or equal to about 75%. Inadditional embodiments, the patient does not experience a pulmonaryexacerbation for at least forty-eight weeks after initiating treatmentwith acebilustat. In some embodiments, the patient is a cystic fibrosispatient undergoing concomitant treatment with a CFTR modulator, such asa CFTR corrector and/or CFTR potentiator. In further aspects, thepatient is not undergoing concomitant treatment with a CFTR modulator,for example, the patient is not undergoing concomitant treatment with aCFTR corrector and/or a CFTR potentiator.

The invention also includes a method of treating cystic fibrosis in apatient in need thereof and/or a method of reducing pulmonaryexacerbations and/or reducing pulmonary inflammation in a cysticfibrosis patient, wherein the patient of the mild lung diseasephenotype, for example, having a FEV₁pp greater than about 65% atbaseline, the method comprising orally administering to the patientacebilustat at a total daily dose of about 100 mg or less. The patientof the mild lung disease phenotype can, for example, have a FEV₁ppgreater than about 68%, greater than about 70%, or greater than about75% at baseline. In yet additional aspects, the patient can, forexample, have a FEV₁pp greater than or equal to about 65%, greater thanor equal to 68%, greater than or equal to about 70%, or greater than orequal to about 75% at baseline. In additional aspects, the acebilustatis administered to the patient at a total daily dose of about 50 mg orless, about 50 mg to about 100 mg, about 100 mg, or about 50 mg. Inspecific aspects, the total daily dose of acebilustat is 100 mg. In someembodiments, the cystic fibrosis patient of the mild lung diseasephenotype is undergoing concomitant treatment with a CFTR modulator,such as a CFTR corrector, and/or a CFTR potentiator. In further aspects,the patient is not undergoing concomitant treatment with a CFTRmodulator, for example, the patient is not undergoing concomitanttreatment with a CFTR modulator, such as a CFTR corrector and/or a CFTRpotentiator. In yet additional aspects, the patient experiences adecrease in the number or frequency of pulmonary exacerbations in thetwelve month period after initiating treatment with acebilustat. Infurther aspects, the patient does not experience a pulmonaryexacerbation for at least forty-eight weeks, for example, at least oneyear, after initiating treatment with acebilustat. In certain aspects,the method comprises measuring FEV₁pp in a patient (at baseline or priorto initiating treatment), for example by spirometry, and administeringacebilustat (at a total daily dose of about 100 mg or less, as describedherein) to the patient if the patient has an FEV₁pp greater than orequal to about 65%, greater than or equal to about 68%, or greater thanor equal to about 70%, or greater than or equal to about 75%.

The invention additionally includes a method of treating cystic fibrosisin a patient in need thereof comprising orally administering to thepatient acebilustat at a total daily dose of about 100 mg or less, about50 mg or less, of about 100 mg, of about 50 mg, or about 50 mg to about100 mg, wherein pulmonary inflammation in the patient is reduced but therisk of pulmonary infection is not increased. In certain aspects, thetotal daily dose of acebilustat administered to the cystic fibrosispatient is 100 mg. In some embodiments, the patient has a mild lungdisease phenotype, for example, a FEV1pp greater than about 65% atbaseline, a FEV₁pp greater than about 68% at baseline, a FEV₁pp greaterthan about 70%, or greater than about 75% at baseline. In yet additionalaspects, the patient can, for example, have a FEV₁pp greater than orequal to about 68% at baseline, greater than or equal to about 70% atbaseline, or greater than or equal to about 75% at baseline. In certainaspects, the method comprises measuring FEV₁pp in a patient (at baselineor prior to initiating treatment), for example by spirometry, andadministering acebilustat (at a total daily dose of about 100 mg orless, as described herein) to the patient if the patient has an FEV₁ppgreater than or equal to about 65%, greater than or equal to about 68%,or greater than or equal to about 70%, or greater than or equal to about75%. In certain aspects, the cystic fibrosis patient is undergoingconcomitant treatment with a CFTR modulator, such as a CFTR correctorand/or CFTR potentiator. In further aspects, the patient is notundergoing concomitant treatment with a CFTR modulator, for example, thepatient is not undergoing concomitant treatment with a CFTR correctorand/or a CFTR potentiator. In yet additional aspects, the patientexperiences a decrease in the rate of pulmonary exacerbations in thetwelve month period after initiating treatment with acebilustat. Infurther aspects, the patient does not experience a pulmonaryexacerbation for at least forty-eight weeks, for example, at least oneyear, after initiating treatment with acebilustat.

The invention further includes methods of decreasing pulmonaryexacerbations, including reducing the rate (for example, number orfrequency) of pulmonary exacerbations or increasing the time to firstpulmonary exacerbation, in a cystic fibrosis patient comprising orallyadministering to the patient acebilustat at a total daily dose of about100 mg or less, wherein the patient is the cystic fibrosis patientundergoing concomitant treatment with a CFTR modulator, such as a CFTRcorrector and/or CFTR potentiator. In certain aspects, the patient doesnot experience any pulmonary exacerbations for at least one year afterinitiating oral administration with acebilustat. Acebilustat can, forexample, be administered at a total daily dose of about 50 mg or less,or about 100 mg, or about 50 mg, about 50 mg to about 100 mg.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a drawing showing the mode of action of Acebilustat(CTX-4430). In many inflammatory diseases, the neutrophil signalingpathway governed by the potent inflammation mediator leukotriene B4(LTB4) and the recovery mediator lipoxin A4 (LXA4) becomes imbalanced,leading to over-activation of neutrophils with sustained inflammationand tissue damage. Acebilustat tunes down the over-active neutrophilresponse by modulating this pathway.

FIG. 2 is a flow chart showing the Phase IIb study design. Randomizationwas stratified by baseline FEV1 percent predicted (50 to 75% and >75%),number of pulmonary exacerbations in the 12 months prior to screening (1or >1) and use of CFTR-modulating therapy such as ivacaftor orlumacaftor and ivacaftor (yes/no).

FIGS. 3A and 3B are bar graphs showing the adjusted mean of annualizedrate of pulmonary exacerbations (PEx) (95% confidence interval) forpatients administered acebilustat at 100 mg, 50 mg, combined treatmentgroups, or placebo (left to right), for the full analysis population(FAP) (FIG. 3A) and per-protocol population (PP) (FIG. 3B) across alllung disease phenotypes.

FIGS. 4A and 4B are Kaplan-Meier plots showing fraction of patientsremaining exacerbation free as a function of time (as a fraction of 364)for patients administered acebilustat at 100 mg, 50 mg, combinedtreatment groups, or placebo, for the full analysis population (FAP)(FIG. 4A) and per-protocol (PP) (FIG. 4B) across all lung diseasephenotypes studied.

FIGS. 5A and 5B are bar graphs showing the percentage of patientstreated with acebilustat or placebo that were exacerbation free over 48weeks for the full analysis population (FAP) (FIG. 5A) and per-protocol(PP) (FIG. 5B) across all lung disease phenotypes.

FIGS. 6A and 6B are bar graphs showing the percentage of patientstreated with 100 mg acebilustat, 50 mg acebilustat, or placebo that wereexacerbation free over 48 weeks for the full analysis population (FAP)(FIG. 6A) and per-protocol (PP) (FIG. 6B) across all lung diseasephenotypes.

FIGS. 7A and 7B are bar graphs showing the adjusted mean of annualizedrate of pulmonary exacerbations (PEx) (95% confidence interval) forpatients treated with acebilustat at 100 mg, 50 mg, or placebo (left toright) for patients having a mild lung disease phenotype characterizedby FEV1pp greater than pooled median of 68% at baseline (FIG. 7B) andpatients having more severe lung disease phenotype, FEV1pp less than orequal to pooled median 68% (FIG. 7A).

FIGS. 8A and 8B are bar graphs showing the adjusted mean of annualizedrate of pulmonary exacerbations (PEx) (95% confidence interval) forpatients treated with acebilustat at 100 mg, 50 mg, combined, or placebo(left to right) for patients having an FEV1pp greater than 75% atbaseline for the full analysis population (FIG. 8A) and per protocolpopulation (FIG. 8B).

FIGS. 9A and 9B are bar graphs showing the adjusted mean of annualizedrate of pulmonary exacerbations (PEx) (95% confidence interval) forpatients treated with acebilustat at 100 mg, 50 mg, or placebo (left toright) for patients having an FEV1pp greater than 75% at baseline (FIG.9A) and patients having an FEV1pp less than or equal to 75% (FIG. 9B)for the full analysis population (FAP).

FIGS. 10A and 10B are Kaplan-Meier plots showing fraction of patientsremaining exacerbation free as a function of time (as a fraction of 364)for patients that had a FEV1pp>75% at baseline and were administeredacebilustat at 100 mg, 50 mg, combined treatment groups, or placebo, forthe full analysis population (FAP) (FIG. 10A) and per-protocol (PP)(FIG. 10B).

FIG. 11 is a bar graph showing the percentage of patients that had aFEV1pp>75% at baseline treated with acebilustat or placebo that wereexacerbation free over 48 weeks for the full analysis population (FAP).

FIGS. 12A and 12B are bar graphs showing the adjusted mean of annualizedrate of pulmonary exacerbations (PEx) (95% confidence interval) forpatients on CFTR modulator therapy administered acebilustat at 100 mg,50 mg, combined treatment groups, or placebo (left to right), for thefull analysis population (FAP) (FIG. 12A) and per-protocol (PP) (FIG.12B).

FIGS. 13A and 13B are Kaplan-Meier plots showing fraction of patientsremaining exacerbation free as a function of time (as a fraction of 364)for patients on CFTR modulator therapy at baseline administeredacebilustat at 100 mg, 50 mg, combined treatment groups, or placebo, forthe full analysis population (FAP) (FIG. 12A) and per-protocol (PP)(FIG. 12B).

FIG. 14 is a forest plot showing the difference in the rate of pulmonaryexacerbations for acebilustat treatment groups (50 mg and 100 mgcombined) versus placebo for the per-protocol analysis set for patientshaving a FEV1pp of 50 to 75% at baseline, patients having a FEV1pp ofgreater than or equal to 75% at baseline, patients having oneexacerbation in the year prior to screening, patients having greaterthan one exacerbation in the year prior to screening, patients that usedCFTR-modulating therapy, patients off CFTR modulator therapy, patientsthat had two or fewer pulmonary exacerbations in the year prior toscreening, patients that had more than one pulmonary exacerbations inthe year prior to screening, patients using azithromycin, and patientsnot treated with azithromycin.

FIGS. 15A and 15B are bar graphs showing the effect of acebilustat onadjusted mean of annualized rate of pulmonary exacerbation in patientshaving baseline FEV1pp>70% (the CF community standard definition of“mild” CF disease; FIG. 15A) compared to patients having baselineFEV1pp>75% (the prespecified definition of “mild” CF used in theclinical study; FIG. 15B).

FIGS. 16A and 16B are bar graphs showing the effect of acebilustat onthe adjusted mean of annualized rate of pulmonary exacerbations inpopulations taking concomitant CFTR modulator therapy (“On”; FIG. 16A)and not taking (“Off”; FIG. 16B) concomitant CFTR modulator therapy.

FIGS. 17A, 17B, and 17C are bar graphs showing percentage ofexacerbation-free patients (treated with acebilustat or placebo) for the48 weeks of the treatment for the mild CF patients (FIG. 17A) and “on”or “off” CFTR modulatory therapy (FIGS. 17B and 17C, respectively).

FIGS. 18A and 18B are bar graphs showing percentage of exacerbation-freepatients treated with 100 mg acebilustat, patients treated with 50 mgacebilustat, and placebo for the 48 weeks of the treatment for patientshaving baseline FEV1pp>75% for the full analysis population (FAP) (FIG.12A) and per-protocol (PP) (FIG. 12B).

FIGS. 19A and 19B are bar graphs showing the estimated effects ofacebilustat at 100 mg and CFTR modulator therapies (KALYDECO®, SYMDEKO®,and ORKAMBI®) on percent reduction in rate of pulmonary exacerbations(FIG. 19A) and percent reduction in risk of pulmonary exacerbations(FIG. 19B).

FIG. 20 is a bar graph showing the effect of acebilustat (50 and 100 mg)on adjusted mean of annualized rate of pulmonary exacerbations requiringhospitalization in patients having baseline FEV1pp>75% for the fullanalysis population (FAP).

FIG. 21 is a bar graph showing the effect of acebilustat (50 and 100 mg)on adjusted mean of annualized rate of pulmonary exacerbations requiringintravenous (IV) antibiotics in patients having baseline FEV1pp>75% forthe full analysis population (FAP).

DETAILED DESCRIPTION OF THE INVENTION

A description of preferred embodiments of the invention follows.

As used herein, the words “a” and “an” are meant to include one or moreunless otherwise specified. For example, the term “an additionaltherapeutic agent” encompasses both a single additional therapeuticagent and a combination of two or more additional therapeutic agents.

It is to be understood that when the range of the dose or amount of adrug or active ingredient (e.g., acebilustat and/or CFTR modulator, suchas CFTR potentiator and/or CFTR corrector, and/or additional therapeuticagent) is described as “between” a low end of the range and “between” ahigh end of the range, the range is meant to include both, the low endand the high end as well as doses in between the low and high ends. Forexample, for “a dose between about 50 mg and about 100 mg,” it is to beunderstood that the range includes the low end of the range, about 50mg, and the high end of the range, about 100 mg, as well as the doses inbetween, for example, about 75 mg. In addition, “a dose of about 50 mgor less” is intended to include the about 50 mg dose as well as dosesless than about 50 mg.

The term “about” as used herein, in reference to a numerical value orrange, allows for a degree of variability in the value or range, forexample, within 10%, within 5%, or within 4%, or within 2% of the valueor range.

The methods of the invention comprise administration of an effectiveoral dose of4-{[(1S,4S)-5-({4-[4-oxazol-2-yl-phenoxy]phenyl}methyl)-2,5-diazabicyclo[2.2.1]heptan-2-yl]methyl}benzoicacid (CTX-4430; Acebilustat) to human patients. This compound andmethods for the preparation thereof have been described in detail inU.S. Pat. Nos. 7,737,145, 9,820,974, and U.S. Patent ApplicationPublication No. 20100210630A1, the contents of each of which areincorporated by reference herein. Acebilustat has the chemical structureshown below:

The invention encompasses methods of reducing pulmonary exacerbations ina patient in need thereof as well as methods of treating pulmonaryinflammation and/or reducing chronic lung inflammation and/or reducingpulmonary inflammation and/or decreasing pulmonary exacerbations in acystic fibrosis patient in need thereof, the methods comprising oraladministration of about 100 mg acebilustat to said patient; for example,chronic oral administration (e.g., for a long period of time and/orthroughout the patient's treatment). The invention also encompasses amethod of reducing pulmonary exacerbations in a patient in need thereofas well as a method of treating pulmonary inflammation and/or reducingchronic lung inflammation and/or reducing pulmonary inflammation and/ordecreasing pulmonary exacerbations in a cystic fibrosis patient in needthereof comprising chronic oral administration of about 50 mgacebilustat to said patient; for example, chronic oral administration(e.g., for a long period of time and/or throughout the patient'streatment). Acebilustat can, for example, be administered at a dose ofabout 50 mg every 12 or 24 hours (or once or twice a day), or at a doseof about 100 mg every 24 hours (or once a day). The inventionadditionally encompasses a method of reducing pulmonary exacerbations ina patient in need thereof as well as a method of treating pulmonaryinflammation and/or reducing chronic lung inflammation and/or reducingpulmonary inflammation and/or decreasing pulmonary exacerbations in acystic fibrosis patient comprising chronic oral administration of about100 mg or less, or of about 50 mg or less, of acebilustat to saidpatient; for example, chronic oral administration (e.g., for a longperiod of time and/or throughout the patient's treatment). The totaldaily dose of acebilustat can be a dose that is 50 mg or less, forexample, about 25 mg, about 15 mg, about 10 mg, or about 5 mg. The totaldaily dose of acebilustat can also be from about 50 mg to about 100 mg,for example, about 75 mg. In certain aspects, the dose of acebilustat isabout 25 mg administered twice a day or a dose between about 25 and 50mg administered twice a day. Acebilustat can be administered with orwithout food.

A major effect of acebilustat treatment is a reduction in pulmonaryexacerbations or a reduction in the rate of pulmonary exacerbations,including a higher proportion of patients that were exacerbation free(or had no pulmonary exacerbations) after initiating acebilustattreatment (as compared to placebo). In certain aspects, the rate orfrequency of pulmonary exacerbations is decreased as compared to thatbefore initiating acebilustat treatment. Pulmonary exacerbations, whichare a clinical marker of lung inflammation, are significant eventsleading to acute decompensation and chronic decline of lung function andare strongly related to reduced survival. The rate of pulmonaryexacerbations is reduced when the number of pulmonary exacerbations in acertain period of time (for example, over forty-eight weeks or a year)is less than that for the same period of time prior to initiating thetreatment and/or as compared to that without acebilustat (for example,treated with placebo or untreated group, and/or as would have beenpredicted from prior medical history). The rate of pulmonaryexacerbation can, for example, be an annual rate of pulmonaryexacerbations or an annualized rate of pulmonary exacerbations. Areduction in the rate, number, or frequency of pulmonary exacerbationsincludes, for example, a reduction of at least about 5%, at least about10%, at least about 15%, at least about 20%, at least about 25%, atleast about 30%, at least about 35%, at least about 40%, at least about45%, at least about 50%, at least about 55%, at least about 60%, atleast about 65%, at least about 70%, at least about 75%, at least about80%, at least about 85%, at least about 90%, and at least about 95%. Incertain aspects, the rate, number, or frequency of pulmonaryexacerbations is reduced by at least about 15%, or at least about 20%,or at least about 25%, or at least about 30%, or at least about 35%, orat least about 40%. When acebilustat is administered concomitantly witha CFTR modulator, the rate, number, or frequency of pulmonaryexacerbations can be reduced by at least about 15%, or at least about20%, or at least about 25% as compared to that with the CFTR modulatorwithout acebilustat. When acebilustat is administered concomitantly witha CFTR modulator to a patient of the mild lung disease phenotype, asdescribed herein, the rate, number, or frequency of pulmonaryexacerbations can, for example, be reduced by at least about 15%, atleast about 20%, at least about 25%, at least about 35%, at least about40%, or at least about 50% as compared to that with the CFTR modulatorwithout acebilustat.

The invention encompasses methods of reducing pulmonary exacerbations,including reducing the number or frequency of pulmonary exacerbations,in a patient in need thereof. A patient in need of such treatment can,for example, be a patient suffering from a respiratory diseasecharacterized by the occurrence of pulmonary exacerbations. Respiratorydiseases include diseases associated with a pathological condition ofthe upper respiratory tract, bronchi, bronchioles, alveoli, pleura,and/or pleural cavity. Non-limiting examples of respiratory diseasescharacterized by pulmonary exacerbations include cystic fibrosis,chronic obstructive pulmonary disease (COPD), bronchiectasis, andinterstitial lung disease. In certain specific embodiments, the patientis suffering from cystic fibrosis. In certain other embodiments, thepatient is suffering from bronchiectasis, including forms of non-cysticfibrosis bronchiectasis such as, but not limited to, primary ciliarydyskinesia or idiopathic bronchiectasis. In yet additional aspects, thepatient is suffering from COPD. In further aspects, the patient issuffering from interstitial lung disease.

In the Phase IIb study described herein, acebilustat treatment was shownto reduce pulmonary exacerbations in cystic fibrosis patients of themild lung disease phenotype (e.g., having an FEV₁pp greater than about65% at baseline) as compared to a matched population taking placebo andas compared to that in acebilustat-treated patients with more severelung disease. Patients having “mild lung disease phenotype” can also bedescribed as being of the mild lung disease subpopulation of CFpatients. The terms “mild lung disease phenotype,” “mild CF disease,”“mild CF,” and “mild disease” in reference to CF patients, are usedinterchangeably herein. The terms “FEV₁pp” and “ppFEV1”, usedinterchangeably, refer to forced expiratory volume in one (1) secondpercent predicted and can be measured using spirometry. The severity oflung disease in cystic fibrosis patients is routinely classifiedaccording to FEV₁pp values. For example, in the literature, mild lungdisease is classified as FEV1pp≥70%, moderate lung disease is classifiedas having a FEV1pp between 40 and 69%, and severe lung disease as havinga FEV1pp of less than 40% (Cystic Fibrosis Patient Registry. 2016.Cystic Fibrosis Foundation. Available on request fromhttps://www.cff.org/Research/Researcher-Resources/Tools-and-Resources/Patient-Registry-Data-Requests/;Davies et al, (2009), Respiratory Care 54(5): 606-617). The severity oflung disease has also been classified as follows in the literature: milddisease is classified as FEV1≥70% predicted; moderate disease isclassified as having FEV1 60-69% predicted; moderately severe lungdisease is classified have a FEV1 50-59% predicted; and severe lungdisease is classified as having FEV1 35-49% predicted; and very severelung disease is classified as having an FEV1<35% predicted. (Morrow etal. (2008), Jornal de Pediatria 84(5): 403-409). In the clinical studydescribed herein, the median FEV1pp for the study population was 68% atbaseline and it was observed that acebilustat-treated patients with aFEV1pp greater than the median experienced a reduced rate of pulmonaryexacerbations and an increase in the time to first pulmonaryexacerbation. It was also observed that acebilustat-treated patientswith a baseline FEV1pp greater than 65% experienced a reduced rate ofpulmonary exacerbations and an increase in the time to first pulmonaryexacerbation (see Table 1 below).

As used herein, a CF patient of the mild lung disease phenotype has abaseline FEV₁pp greater than or equal to about 65%. A patient of themild lung disease phenotype can, for example, have a baseline FEV₁ppgreater than or equal to about 68%, a baseline FEV₁pp greater than orequal to about 70%, or a baseline FEV1pp greater than or equal to about75%. Therefore, in certain aspects, the method comprises treating apatient having a FEV₁pp greater than or equal to about 65% at baselinewith acebilustat at a dose of about 100 mg or less, or about 50 mg orless; for example, a daily dose of about 100 mg or a daily dose of about50 mg. In certain aspects, the patient has a baseline FEV₁pp greaterthan or equal to about 68%, greater than or equal to about 70%, orgreater than or equal to about 75% at baseline. In certain additionalaspects, the patient can have a FEV₁pp greater than about 70%, orgreater than about 75% at baseline. The inventive methods can alsoinclude measuring baseline FEV₁pp in a patient (at baseline or prior toinitiating treatment), for example by spirometry, and administeringacebilustat to the patient if the patient has an FEV₁pp greater than orequal to about 65%, greater than or equal to about 68%, or greater thanor equal to about 70%, or greater than or equal to about 75%. A FEV₁ppat baseline is the FEV₁pp measured pre-treatment, for example, at apoint in time prior to or shortly prior to the first administration ofacebilustat, or in other words, prior to the initiation of acebilustattreatment, or is the FEV₁pp at the start or initiation of treatment.

Acebilustat can be administered to a patient, such as a cystic fibrosispatient (regardless of disease phenotype), on top of their currenttreatment regime, or on top of the standard of care. The standard ofcare for the treatment of cystic fibrosis patients includes, but is notlimited to, mucolytics, antibiotics, and CFTR modulators, or acombination thereof. The standard of care for the treatment of chronicobstructive pulmonary disease (COPD) includes, but is not limited to,bronchodilators, beta-agonists, anticholinergics, glucocorticoids, or acombination thereof. The standard of care for the treatment ofinterstitial lung disease includes, but is not limited to,glucocorticoids, cyclophosphamide, azathioprine, methotrexate, andmycophenolate mofetil, or a combination thereof. The standard of carefor the treatment of bronchiectasis includes, but is not limited to,bronchodilators, steroids, and antibiotics such as penicillinantibiotics and inhaled antibiotics including tobramycin and aztreonam,as well as combinations of any of thereof. The additional therapeuticagent(s) that can comprise a patient's treatment regimen are discussedin more detail below. Acebilustat can be administered concomitantly tocystic fibrosis patients with an additional therapeutic agent including,for example, a CFTR modulator and/or a CFTR amplifier. As used herein,the term “CFTR modulator” includes an agent or compound that modulates(for example, increases) the activity of CFTR; in certain specificaspects, the CFTR modulator increases the activity of a CFTR protein.The increase in activity resulting from a CFTR modulator includes, butis not limited to, compounds that correct, potentiate, stabilize and/oramplify CFTR. As such, the term “CFTR modulator” as used herein includesCFTR correctors, CFTR potentiators, CFTR stabilizers, and CFTRamplifiers. A CFTR corrector is an agent or compound that increases theamount of functional CFTR protein to the cell surface, resulting inenhanced ion transport. A CFTR potentiator is an agent or compound thatincreases the channel activity of CFTR protein located at the cellsurface, resulting in enhanced ion transport. A CFTR stabilizer resultsin an elongated presence of CFTR in the epithelial cell membrane. A CFTRamplifier is an agent that enhances the effect of a CFTR potentiator,corrector, and/or stabilizer. That acebilustat provides a benefit whenused in combination with a CFTR modulator is important given the numberof cystic fibrosis patients currently treated with CFTR modulators andthe likelihood of an increase in number of cystic fibrosis patients whoare eligible to be treated with new CFTR modulators over the comingyears.

Concomitant treatment or administration of acebilustat and a CFTRmodulator, including, but not limited to, CFTR potentiator and/or CFTRcorrector, or any other additional therapeutic agent, is intended tomean administration of acebilustat and the additional therapeutic agentat such time that both will have a therapeutic effect and/orco-administration of the agents, for example, as part of the sametreatment regimen. Such concomitant administration can involveconcurrent (i.e., at the same time), prior, or subsequent administrationof acebilustat with respect to the administration of the additionaltherapeutic agent. For example, the initiation of acebilustat treatmentcan be subsequent to the initiation of treatment with a CFTR modulatorsuch as a CFTR corrector and/or CFTR potentiator; for example, thepatient can have undergone treatment with the CFTR modulator for severalweeks, months, or years, prior to initiating treatment with acebilustat.It is to be understood that when acebilustat is co-administered with theat least one additional therapeutic agent (e.g., a CFTR potentiatorand/or a CFTR corrector and/or other therapeutic agent), the compoundcan be administered simultaneously with, prior to, or afteradministration of one or more other therapeutic agents. Such combinationtherapy includes administration of a single pharmaceutical dosageformulation which contains the acebilustat and the one or moreadditional active agents, as well as administration of the acebilustatand each active agent in its own separate pharmaceutical dosageformulation. For example, the acebilustat and the other therapeuticagent can be administered to the patient together in a single oraldosage composition such as a tablet or capsule, or each agent can beadministered in separate oral dosage formulations. Where separate dosageformulations are used, acebilustat and one or more additional activeagents can be administered at essentially the same time, i.e.,concurrently, or at separately staggered times, i.e., sequentially;and/or in the same treatment session and/or as part of the sametreatment regimen; and/or daily administration of acebilustat and dailyadministration of the one or more additional active agents. Combinationtherapy and concomitant administration is understood to include allthese regimens.

As described in more detail below, the Phase IIb study was designed inorder to provide the first proof-of-concept for an anti-inflammatorytherapy (acebilustat) designed to prevent or reduce progressive loss oflung function by reducing pulmonary exacerbations in cystic fibrosis(CF) patients. The primary analysis was based upon an analysis ofvariance (ANOVA) in which the average of the Week 48 change frombaseline in FEV₁pp for the two acebilustat doses was compared to that inthe placebo group. The ANOVA model contained a separate term for eachdose group with the average over the two acebilustat doses created byaveraging the parameter estimates from the ANOVA model. In addition toterms for treatment group, the ANOVA included stratification for thefactors used for randomization. For example, stratified factors includebaseline lung function, frequency of pulmonary exacerbations in theprior year, and concomitant CFTR modulator use. The analysis fordifference in pulmonary exacerbations may include contrast analysesusing confidence intervals, t-test of simple means, Poisson regressionand, most preferably, negative binomial regression.

In addition, it was believed that certain subsets of the general cysticfibrosis (CF) population are at greater risk for rapid lung functiondecline, and that this subset can provide a study population that isaffected by active inflammation, and that also experiences a decline ofadequate magnitude to detect clinical benefit over a 48-week interval.Such a subset was identified through research of the Cystic FibrosisPatient Registry (CFPR) and based on knowledge of the projected rate ofdecline of FEV₁pp and the frequency of pulmonary exacerbations in thissubpopulation. For example, prior pulmonary exacerbations are one of thestrongest predictors of a future pulmonary exacerbation [Block et al.,2006; VanDevanter et al., 2016]. Furthermore, it has been estimated thatup to half of lung function decline is related to pulmonaryexacerbations [Waters et al., 2012] and that exacerbations are a clearindicator of active neutrophil driven inflammation (see for example,Ngan et al. (2012), BMC Pulmonary Medicine 12:3; Wojewodka et al.(2014), PLOS One 9(2), e88567). Susceptibility to annual decline in lungfunction is greatest from adolescence to early adulthood and attenuatesafter patients reach approximately 30 years of age [Liou et al., 2010].Additionally, patients with a higher baseline lung function may also bemore susceptible to greater declines in FEV₁pp [Konstan et al., 2012].Additionally, CF patients 15 to 30 years of age are more likely toexperience pulmonary exacerbations [CFF Registry Report, 2017].

Based on these published observations, data from the CFPR [CysticFibrosis Foundation, 2014] was analyzed for different age ranges (12-17years, 18-30 years, 31-35 years, or 36-39 years); baseline FEV₁pp(50-59%, 60-79%, 80-99%, or ≥100%) and number of pulmonary exacerbationsrequiring use of an IV antibiotic in the prior year (0 or ≥1). Theregistry data provided support for the concept that patients 12-30 yearsold who had had at least one pulmonary exacerbation in the prior yearwere at highest risk for rapid lung function decline. Within thissubgroup, the registry data provided further evidence that patients witha higher FEV₁pp at baseline were likely to have the most rapid declinein FEV₁pp. Within the subgroup of 18-30 years' old, CF patients who hadhad at least one pulmonary exacerbation in the prior year, the presentyear rate of decline is estimated to be 3.47 percentage points per year.Detection of differences in rate of FEV₁pp decline on the order of 3percentage points per year requires observation over at least 48 weeks.Thus, the patient population for the current study was enriched based onoptimal patient age, FEV₁pp and exacerbation history, in order to detecta change in rate of FEV₁ decline and change in exacerbation rate over 48weeks in a Phase II study as compared to placebo. This population andstudy duration is in line with published guidance from the CysticFibrosis Foundation (CFF). [Torphy et al., 2015]. Thus, patients for thePhase IIb study were selected based on stringent inclusion criteria (age18-30 years, FEV₁pp≥50, and at least one exacerbation in the past year).This enriched the study population with patients who are mostsusceptible to pulmonary exacerbations and annual lung function decline.It is also believed that this population of patients will achievegreater benefit from acebilustat treatment with respect to decreasedlung function decline than other populations.

As discussed above, it was believed that patients most likely to benefitfrom acebilustat treatment, including combination treatment with a CFTRpotentiator and/or CFTR corrector, include patients that are ≤30 yearsold (for example, between about 12 to about 30 years old), and/orpatients that had at least one pulmonary exacerbation in the year priorto the first administration of acebilustat and/or patients that have aFEV₁pp≥about 50%, as described in more detail below.

The results of the study are shown in FIGS. 3 to 21 and described in theExample. It was found that the major effect of acebilustat was areduction in the rate of pulmonary exacerbations (PEx) as compared toplace and reduced risk of progression to pulmonary exacerbations. Thesebenefits were most notable for patients of the mild disease phenotype(for example, FEV1pp greater than 75 at baseline) as well as in patientstaking CFTR modulator therapy. Patients with less severe impairment oflung function or having a mild lung disease phenotype (specifically,FEV1pp greater than 75) achieved the largest benefit from acebilustattherapy in the analysis of data from the combined 50 mg and 100 mg dosegroups compared to placebo, achieving about 35% reduction in PEx rate(48% reduction for the 100 mg dose) versus placebo, about 43% reductionin risk of experiencing their first exacerbation (48% reduction in riskfor the 100 mg dose) versus placebo and an about 96% higher proportionpatients who were exacerbation free after 48 weeks of treatment (100%higher for the 100 mg dose). Furthermore, patients concomitantly treatedwith CFTR modulator therapy and acebilustat regardless of diseaseseverity phenotype exhibited a clinically meaningful about 20% reductionin rate of PEx (14% reduction for the 100 mg dose), about 29% increasedtime to first exacerbation (27% increase for the 100 mg dose) and about47% higher proportion of patients with no exacerbations compared topatients treated with CFTR modulators and placebo (51% higher for the100 mg dose). In addition, for patients off CFTR modulator therapy,about 15% higher percentage of patients that were exacerbation free wasobserved. Furthermore, patients with an FEV1pp greater than 75 andtreated concomitantly with CFTR modulator therapy exhibited a 54%decrease in the rate of pulmonary exacerbations (65% reduction for the100 mg dose) and a 165% higher proportion of patients who wereexacerbation free at 48 weeks as compared to patients that were treatedwith placebo instead of acebilustat.

A pulmonary exacerbation for the purposes of the clinical trial isdefined as the requirement for oral, inhaled or intravenous antibioticsfor four or more signs or symptoms according to the modified Fuchs'criteria (change in sputum; new or increased hemoptysis; increasedcough; increased dyspnea; malaise, fatigue or lethargy; temperature >38°C.; anorexia or weight loss; sinus pain or tenderness; change in sinusdischarge; change in physical examination of the chest; ≥10% absolutedecrease in FEV₁pp from the previously recorded value; radiographicchanges indicative of pulmonary infection) [Fuchs et al., 1994],referred collectively (antibiotics plus the four or more signs andsymptoms) as expanded Fuchs criteria. A pulmonary exacerbation can bedefined according to the Fuchs criteria, the expanded Fuchs criteria, orby other criteria known in the art (including, for example, need foradditional treatment as indicated by a recent change in clinicalparameters) and/or according to the judgement or determination of aphysician [Bilton et al. (2011), Journal of Cystic Fibrosis 10 (Suppl2): S79-S81; Dakin et al. (2001), Pediatr Pulmonol. 31: 436-442, thecontents of each of which are expressly incorporated by referenceherein]. Pulmonary exacerbations are typically accompanied by thesubsequent treatment of the CF or other respiratory disease patient witha course of antibiotics. For the purposes of a clinical trial and themethods described herein, the date the pulmonary exacerbation began canbe defined as the first day of antibiotic use or as the date of theonset of symptoms.

In certain aspects, the method comprises identifying a cystic fibrosispatient that has had at least one pulmonary exacerbation in the prioryear (in other words, in the about twelve month period or about 52 weekperiod prior to the initiation of treatment) and treating such a patientwith acebilustat at total oral daily dose of about 50 mg to about 100mg, or about 100 mg or less, or about 50 mg or less, or about 100 mg, orabout 50 mg. The method can also include identifying a cystic fibrosispatient that has had at least one pulmonary exacerbation in the prioryear, and treating such a patient with acebilustat at a total oral dailydose of about 50 mg to about 100 mg, or about 100 mg or less, or about50 mg or less, or about 100 mg, or about 50 mg. In addition, the methodcan include identifying a patient that has had two or more, or more thantwo pulmonary exacerbations in the prior year, and treating such apatient with acebilustat at a total oral daily dose of about 50 mg toabout 100 mg, or about 100 mg or less, or about 50 mg or less, or about100 mg, or about 50 mg. In certain additional aspects, the methodcomprises identifying a cystic fibrosis patient that has had at leastone pulmonary exacerbations within the past two years, within the pastthree years, within the past four years, or within the past five years,and treating such a patient with acebilustat at a total oral daily doseof about 50 mg to about 100 mg, or about 100 mg or less, or about 50 mgor less, or about 100 mg, or about 50 mg. The methods includeidentifying a cystic fibrosis patient that has had at least onepulmonary exacerbation, two or more pulmonary exacerbations, or morethan two pulmonary exacerbations, within the prior year, the past twoyears, within the past three years, within the past four years, orwithin the past five years, and treating such a patient with acebilustatat a total oral daily dose of about 50 mg to about 100 mg, or about 100mg or less, or about 50 mg or less, or about 100 mg, or about 50 mg.

The Phase 2b study includes stratification based on concomitant CFTRmodulator use. This is important since about half of cystic fibrosispatients in the U.S. are currently treated with CFTR modulators.Stratification based on concomitant CFTR modulator use was alsoconsidered important as neutrophil elastase is shown to downregulateCFTR [Le Gars et al., 2013]; and it was believed that acebilustat, whichhas been shown to reduce neutrophil elastase [Elborn et al., 2017], mayhave synergistic effects with CFTR modulators, including CFTRpotentiators and/or CFTR correctors.

The methods include orally administering to a cystic fibrosis patientacebilustat at a total daily dose of about 100 mg or less, of about 50mg or less, or from about 50 mg to about 100 mg, or a total daily doseof about 100 mg, or a total daily dose of about 50 mg. As describedherein, the patient treated with acebilustat can be undergoingconcomitant CFTR modulator therapy (regardless of lung diseasephenotype) wherein a therapeutically effective amount of a CFTRpotentiator and/or a CFTR corrector is concomitantly administered tosaid patient. A preferred CFTR potentiator is ivacaftor (KALYDECO®).Preferred CFTR correctors are lumacaftor and tezacaftor. In certainaspects, one CFTR potentiator and at least one CFTR corrector areadministered. For example, a combination including ivacaftor can beadministered; for example, a combination of ivacaftor and lumacaftor,preferably ORKAMBI® (lumacaftor/ivacaftor) is administered. The methodincludes administering at least two CFTR correctors, or at least oneCFTR corrector and at least one CFTR potentiator. For example, acombination of ivacaftor and lumacaftor, preferably ORKAMBI®(lumacaftor/ivacaftor) can be administered. In other examples, two CFTRcorrectors can be administered, optionally with a CFTR potentiator; thecombination can, for example, include ivacaftor. As described above,acebilustat can, for example, be administered at a dose of about 50 mgevery 12 or 24 hours (or once or twice a day), or at a dose of about 100mg every 24 hours (or once a day). Acebilustat can also be administeredat a total daily dose of 50 mg or less, wherein acebilustat isadministered once or multiple times a day. When the treatment includesadministration of ivacaftor, an exemplary oral dose is 150 mg every 12hours (or twice a day) and/or at a total daily dose of about 300 mg. Forpatients aged 2 to 6 years old, an exemplary oral dose of ivacaftor is50 mg or 75 mg twice a day. When the treatment includes administrationof lumacaftor/ivacaftor (as a combination, for example, ORKAMBI®), thetotal daily dose of lumacaftor administered is about 800 mg and thetotal daily dose of ivacaftor administered is about 500 mg for patientsaged 12 years and over. For patients between the ages of 6 and 11treated with ORKAMBI®, the total daily dose of lumacaftor administeredis 400 mg and the total daily dose of ivacaftor administered is about500 mg. Certain triple combination regimens comprising ivacaftor, suchas ivacaftor, tezacaftor, and another corrector have also been describedfor the treatment of cystic fibrosis. Thus, the invention encompassesadministration of acebilustat, as described herein, in combination witha triple combination regimen; optionally, wherein the triple combinationregimen comprises ivacaftor. In certain embodiments, the invention isdirected to a method comprising administering acebilustat and a triplecombination regimen, for example, such a triple combination can includetezacaftor plus ivacaftor and one of the following: VX-445, VX-659,VX-440 or VX-152. In other embodiments the triple combination can becomprised of other CFTR modulators. In yet other embodiments thecombination may be comprised of four or more such CFTR modulators.

Cystic fibrosis is caused by loss-of-function mutation(s) in the cysticfibrosis membrane conductance regulator (CFTR) gene. CFTR is a membraneprotein and chloride channel. There are more than 1,800 mutations thathave been discovered in the CFTR gene, which are characterized into fiveclasses. The most often occurring mutation is F508del (deletion ofphenylalanine at position 508), a Class II mutation, in which the CFTRprotein does not reach the cell surface due to misfolding. As will beunderstood, a person can have a F508del mutation on one allele and othermutation on the other allele (heterozygous), or on both alleles(homozygous). Other mutations include Class III mutations, such as G551Dand S549N, where CFTR reaches the cell surface but the channel hascompromised function. The patient to be treated according to thedescribed methods can, for example, have a F508del mutation (eitherheterozygous or homozygous), and/or have a CFTR functional mutation(Classes III-VI or III to VI, depending on the classification systemused), or have a non-F508del mutation. Exemplary mutations in additionto F508del are E56K, P67L, R74W, D110E, D110H, R117C, R17H, E193K,L206W, R347H, R352Q, A455E, D579G, S945L, S977F, F1052V, K1060T, A1067T,G1069R, R1070Q, R1070W, F1074L, D1152H, D1270N, G551D, G178R, S549R,S549N, G551S, G1244E, S1251N, S1255P, and G1349D. CFTR correctorsincrease the amount of functional CFTR protein at the cell surface,resulting in enhanced ion transport. CFTR potentiators are compoundsthat increase the channel activity of the CFTR on the cell surface (forexample, in patients with a gating mutation). CFTR correctors, forexample, can target patients with the F508del mutation. The method oftreatment can include treating patients with a F508del mutation andtreating patients with a non-F508del patient.

In yet additional embodiments, the invention is directed to a method oftreating cystic fibrosis or a method of reducing pulmonary inflammationor a method of treating chronic lung inflammation and/or decreasingpulmonary exacerbations in a cystic fibrosis patient in need thereofcomprising administering to said patient acebilustat at a total dailydose of about 100 mg or less, or about 50 mg or less, or from about 50mg to about 100 mg, or about 100 mg, or about 50 mg, wherein saidpatient is not undergoing concomitant treatment with a CFTR modulatorsuch as a CFTR corrector/and or CFTR potentiator and/or CFTR amplifier.Such patients include, but are not limited to, patients of the mild lungdisease phenotype as described herein. In certain aspects, the patientis not undergoing concomitant treatment with a CFTR corrector. Inadditional aspects, the patient is not undergoing concomitant treatmenta CFTR potentiator. In yet additional aspects, the patient is notundergoing concomitant treatment with either a CFTR corrector or a CFTRpotentiator, or a combination thereof. In further aspects, the totaldaily dose of acebilustat administered to the cystic fibrosis patientnot undergoing treatment with a CFTR corrector and/or CFTR potentiatoris about 50 mg. In additional aspects, the total daily dose ofacebilustat administered to the cystic fibrosis patient not undergoingtreatment with a CFTR corrector and/or CFTR potentiator is about 100 mg.In yet additional aspects, the total daily dose of acebilustatadministered to the cystic fibrosis patient not undergoing treatmentwith a CFTR corrector and/or CFTR potentiator is about 50 mg or less. Infurther aspects, the total daily dose of acebilustat administered to thecystic fibrosis patient not undergoing treatment with a CFTR correctorand/or CFTR potentiator is about 100 mg or less.

In additional aspects, the methods comprise administering acebilustat toa cystic fibrosis patient, wherein the patient is 30 years old oryounger. In further aspects, the patient is two years or older, sixyears or older, 12 years and older, 18 years and older, about six to 12years old, about 12 to about 30 years old, or about 18 to about 30 yearsold. In yet additional aspects, the patient is greater than 30 yearsold. In further aspects, the patient is 18 years or older.

The invention encompasses methods of reducing pulmonary inflammationand/or decreasing pulmonary exacerbations in a cystic fibrosis patientin need thereof comprising administering to the patient atherapeutically effective amount of acebilustat as described herein,wherein the patient is greater than 6 years older, two years or older,six years or older, 12 years or older, 18 years or older, 30 years orolder, between about 6 years and 12 years old, between about 6 years oldand about 30 years old, between about 12 and about 30 years old, orbetween about 18 and about 30 years and has had at least one pulmonaryexacerbation in the year prior to the first administration ofacebilustat. The invention additionally encompasses methods of treatingcystic fibrosis, reducing pulmonary inflammation, and/or treatingchronic lung inflammation and/or decreasing pulmonary exacerbations in acystic fibrosis patient in need thereof comprising administering to thepatient a therapeutically effective amount of acebilustat as describedherein, wherein the patient is six years or older, two years or older,six years or older, 12 years or older, 18 years or older, 30 years orolder, between about 6 years and 12 years old, between about 12 to about30 years old, or between about 18 and about 30 years and has had two orfewer pulmonary exacerbations in the year prior to the firstadministration of acebilustat. In further aspects, the patient is aboutsix years old or older, two years or older, six years or older, 12 yearsor older, 18 years or older, 30 years or older, between about 6 yearsand 12 years old, between about 12 and about 30 years old, or betweenabout 18 and about 30 years old and has a FEV₁pp greater than or equalto about 65%, greater than or equal to about 68%, greater than or equalto about 70%, or greater than or equal to about 75%.

The invention also encompasses methods of reducing pulmonaryinflammation and/or decreasing pulmonary exacerbations in a cysticfibrosis patient in need thereof comprising administering to the patienta therapeutically effective amount of acebilustat, wherein the patientis 30 years old or older and has had at least one pulmonary exacerbationin the year prior to the first administration of acebilustat. In certainaspects, the patient is 30 years old or older and has had two or fewerpulmonary exacerbations in the year prior to the first administration ofacebilustat. In further aspects, the patient is 30 years old or olderand has a FEV₁pp greater than about 65%, greater than to about 68%,greater than about 70%, greater than about 75%, greater than or equal to65%, greater than or equal to 68%, greater than or equal to about 70%,or greater than or equal to about 75%.

The methods described herein are useful for treating chronic lunginflammation and/or reducing pulmonary inflammation in a cystic fibrosispatient. In certain aspects, chronic lung inflammation is treated and/orpulmonary inflammation is reduced when there is a decrease in the numberof pulmonary exacerbations and/or attenuation in the rate of lungfunction decline. With respect to a decrease in pulmonary exacerbationsin CF or other respiratory disease patient, the decrease in pulmonaryexacerbations can also be a decrease in the annualized rate of pulmonaryexacerbations. In addition, the number of pulmonary exacerbationsexperienced by the CF or other respiratory disease patient in the six(6), twelve (12), twenty-four (24), thirty-six (36), or forty-eight (48)month period after initiating the treatment (comprising acebilustat) canbe decreased as compared to that in the six, twelve, twenty-four,thirty-six, or forty-eight month period, respectively, prior toinitiating the treatment. For example, where the patient had experiencedtwo pulmonary exacerbations in the twelve month period prior toinitiating the treatment, a reduction in chronic lung inflammation orpulmonary inflammation can be evidenced by a reduction in the number ofpulmonary exacerbations (e.g., only one or no pulmonary exacerbations)in the twelve month period after initiating the treatment. In certainaspects, the CF or other respiratory disease patient is exacerbationfree for the six (6), twelve (12), twenty-four (24), thirty-six (36), orforty-eight (48) month period after initiating the treatment (comprisingacebilustat). In certain specific aspects, the CF patient isexacerbation free for the six (6), twelve (12), twenty-four (24),thirty-six (36), or forty-eight (48) month period after initiating thetreatment (comprising acebilustat).

In addition, chronic lung inflammation is treated and/or pulmonaryinflammation is reduced when the rate of lung function decline isattenuated after initiating the treatment (comprising acebilustat) ascompared to that prior to initiating the treatment.

The acebilustat treatment is “initiated” at the time the first dose ofacebilustat is administered; thus, for example, the six month periodafter initiating the treatment is the six month period from the day ordate the first dose of acebilustat is administered and the six monthperiod prior to initiating the treatment is the six month period priorto the day or date the first dose of acebilustat is administered.

As used therein, a “therapeutically effective amount” or an “effectiveamount” refers to that amount of a compound or drug that, whenadministered to a mammal, preferably a human, is sufficient to effecttreatment, as defined below, of a disease or condition of interest inthe mammal, preferably a human. The amount of a compound of theinvention which constitutes a “therapeutically effective amount” or an“effective amount” will vary depending on, for example, the activity ofthe specific compound employed; the metabolic stability and length ofaction of the compound; the age, body weight, general health, sex, anddiet of the patient; the mode and time of administration; the rate ofexcretion; the drug combination; the severity of the particular disorderor condition; and the subject undergoing therapy, but it can bedetermined routinely by one of ordinary skill in the art having regardto his own knowledge and to this disclosure.

“Treating” or “treatment” as used herein covers the treatment of thedisease or condition of interest in a mammal, preferably a human, havingthe disease or condition of interest, and includes, for example: (i)inhibiting or decreasing the severity of the disease or condition, orone or more symptoms thereof, i.e., arresting or slowing development orprogression of the disease or condition, and/or ameliorating one or moresymptoms; (ii) relieving the disease or condition, i.e., causingregression of the disease or condition, or one more symptoms thereof;and/or (iii) stabilizing the disease or condition. In addition,“treating” or “treatment” in the context of cystic fibrosis can includetreating chronic lung inflammation and/or decreasing pulmonaryinflammation such as by reducing pulmonary exacerbations (for example,reducing the rate, number, or frequency of pulmonary exacerbation orincreasing the time to first pulmonary exacerbation), attenuating thedecline in lung function, increasing lung function, reducinginflammation (including reducing neutrophil-induced inflammation),reducing neutrophil influx, increasing FEV₁pp, and/or slowing thedecrease in FEV₁pp, or a combination thereof, as described herein. Inthe context of treating a respiratory disease characterized by pulmonaryexacerbations, “treating” or “treatment” can include reducing pulmonaryexacerbations (for example, reducing the rate, number, or frequency ofpulmonary exacerbation or increasing the time to first pulmonaryexacerbation).

As used herein, the terms “disease” and “condition” may be usedinterchangeably or may be different in that the particular malady orcondition may not have a known causative agent (so that etiology has notyet been worked out) and it is therefore not yet recognized as a diseasebut only as an undesirable condition or syndrome, wherein a more or lessspecific set of symptoms have been identified by clinicians.

A “pharmaceutical composition” refers to a formulation of a compounddescribed herein, for example, acebilustat and/or a CFTR modulator, anda medium generally accepted in the art for the delivery of thebiologically active compound to mammals, for example, humans. Such amedium includes all pharmaceutically acceptable carriers, diluents orexcipients.

“Optional” or “optionally” means that the subsequently described eventof circumstances may or may not occur, and that the description includesinstances where said event or circumstance occurs and instances in whichit does not.

“Pharmaceutically acceptable excipient” includes without limitation anyadjuvant, carrier, excipient, glidant, sweetening agent, diluent,preservative, dye/colorant, flavor enhancer, surfactant, wetting agent,dispersing agent, suspending agent, stabilizer, isotonic agent, solvent,or emulsifier which, for example, has been approved by the United StatesFood and Drug Administration as being acceptable for use in humans ordomestic animals.

Administration of the compounds or drugs described herein encompassesadministration of a pharmaceutically acceptable salt of said compound ordrug, for example, administration of a pharmaceutically acceptable saltof acebilustat or a pharmaceutically acceptable salt of a CFTRmodulator. Administration of the compounds or drugs as described herein(such as acebilustat, a CFTR modulator or other additional therapeuticagent), or their pharmaceutically acceptable salts, in pure form or inan appropriate pharmaceutical composition, can be carried out via any ofthe accepted modes of administration of agents for serving similarutilities. As described herein, the preferred mode of administration foracebilustat is oral administration. The pharmaceutical compositionsdescribed herein can be prepared by combining a compound or drug with anappropriate pharmaceutically acceptable carrier, diluent or excipient,and may be formulated into preparations in solid, semi-solid, liquid orgaseous forms, such as tablets, capsules, powders, granules, ointments,solutions, suppositories, injections, inhalants, gels, microspheres, andaerosols. Typical routes of administering such pharmaceuticalcompositions include, without limitation, oral, topical, transdermal,inhalation, parenteral, sublingual, rectal, vaginal, and intranasal. Theterm parenteral as used herein includes subcutaneous injections,intravenous, intramuscular, intrasternal injection or infusiontechniques. Pharmaceutical compositions of the invention are formulatedso as to allow the active ingredients contained therein to bebioavailable upon administration of the composition to a patient.Compositions that will be administered to a subject or patient take theform of one or more dosage units, where for example, a tablet may be asingle dosage unit, and a container of a compound of the invention inaerosol form may hold a plurality of dosage units. Actual methods ofpreparing such dosage forms are known, or will be apparent, to thoseskilled in this art; for example, see The Science and Practice ofPharmacy, 20^(th) Edition (Philadelphia College of Pharmacy and Science,2000). The composition to be administered will, in any event, contain atherapeutically effective amount of the compound or drug, or apharmaceutically acceptable salt thereof, for treatment of a disease orcondition of interest in accordance with the teachings of thisinvention.

A pharmaceutical composition can be in the form of a solid or liquid. Inone aspect, the carrier(s) are particulate, so that the compositionsare, for example, in tablet or powder form. In one aspect, thecomposition can be an encapsulated powder or granular form. In anotheraspect, an encapsulated powder or granular formulation can be opened andsprinkled in food or administered by gastric intubation. The carrier(s)can be liquid, with the compositions being, for example, an oral syrup,injectable liquid or an aerosol, which is useful in, for example,inhalatory administration. When intended for oral administration, thepharmaceutical composition can be in either solid or liquid form, wheresemi-solid, semi-liquid, suspension and gel forms are included withinthe forms considered herein as either solid or liquid.

As a solid composition for oral administration, the pharmaceuticalcomposition may be formulated into a powder, granule, compressed tablet,pill, capsule, chewing gum, wafer or the like form. Such a solidcomposition will typically contain one or more inert diluents or ediblecarriers. In addition, one or more of the following may be present:binders such as carboxymethylcellulose, ethyl cellulose,microcrystalline cellulose, gum tragacanth or gelatin; excipients suchas starch, lactose or dextrins, disintegrating agents such as alginicacid, sodium alginate, Primogel, corn starch and the like; lubricantssuch as magnesium stearate or Sterotex; glidants such as colloidalsilicon dioxide; sweetening agents such as sucrose or saccharin; aflavoring agent such as peppermint, methyl salicylate or orangeflavoring; and a coloring agent.

When the pharmaceutical composition is in the form of a capsule, forexample, a gelatin capsule, it may contain, in addition to materials ofthe above type, a liquid carrier such as polyethylene glycol or oil.

The pharmaceutical composition can be in the form of a liquid, forexample, an elixir, syrup, solution, emulsion or suspension. The liquidcan be for oral administration or for delivery by injection, as twoexamples. When intended for oral administration, a composition cancontain, in addition to the present compounds, one or more of asweetening agent, preservatives, dye/colorant and flavor enhancer. In acomposition intended to be administered by injection, one or more of asurfactant, preservative, wetting agent, dispersing agent, suspendingagent, buffer, stabilizer and isotonic agent may be included.

The liquid pharmaceutical compositions of the invention, whethersolutions, suspensions or other like form, can include one or more ofthe following adjuvants: sterile diluents such as water for injection,saline solution, preferably physiological saline, Ringer's solution,isotonic sodium chloride or physiological saline, fixed oils such assynthetic mono or diglycerides which may serve as the solvent orsuspending medium, polyethylene glycols, glycerin, propylene glycol orother solvents; antibacterial agents such as benzyl alcohol or methylparaben; antioxidants such as ascorbic acid or sodium bisulfite;chelating agents such as ethylenediaminetetraacetic acid; buffers suchas acetates, citrates or phosphates and agents for the adjustment oftonicity such as sodium chloride or dextrose. The parenteral preparationcan be enclosed in ampoules, disposable syringes or multiple dose vialsmade of glass or plastic. Physiological saline is a preferred adjuvant.An injectable pharmaceutical composition is preferably sterile.

The invention includes methods wherein acebilustat is administered withan additional therapeutic agent, for example, that is part of thestandard of care for the respiratory disease suffered by the patient,including, for example, cystic fibrosis, chronic obstructive pulmonarydisease, bronchiectasis, and interstitial lung disease. The inventionspecifically encompasses methods wherein acebilustat is administeredwith an additional therapeutic agent (for example, that is part of thestandard of care for cystic fibrosis), or the combination of acebilustatand a CFTR potentiator and/or CFTR corrector is co-administered with anadditional therapeutic agent. The additional therapeutic agent can, forexample, be a drug used in the treatment of cystic fibrosis can include,but is not limited to, a bronchodilator, an antibiotic, a mucolytic, asurfactant, a pancreatic enzyme replacement drug, a CFTR modulator, or acombination thereof. In further aspects, the invention encompassesmethods wherein acebilustat or the combination of acebilustat and a CFTRmodulator such as CFTR potentiator and/or CFTR corrector is combinedwith an airway clearance technique. Such airway clearance techniquesinclude coughing or huffing and can include percussion (clapping) orvibration. In additional aspects, acebilustat or the combinationacebilustat and a CFTR modulator, such as CFTR potentiator and/or CFTRcorrector, is combined with gene therapy (including the administrationof agents used for gene therapy, such as, retroviral vectors or genomeediting reagents) and gene editing techniques such as those which usethe CRISPR/Cas9 system.

In some embodiments, the additional therapeutic agent used in thetreatment of CF or other respiratory disease is a beta-agonist.Exemplary beta-agonists are albuterol, salbutamol, levalbuterol,formoterol, fenoterol, salmeterol, bambuterol, brocaterol, clenbuterol,terbutalin, tulobuterol, epinephrin, isoprenalin, and hexoprenalin. Inanother embodiment, the yet additional therapeutic agent is ananticholinergic agent. Exemplary anticholinergics are tiotropium,oxitropium, ipratropium, and glycopyrrolate. In a further embodiment,the additional therapeutic agent is a mucolytic and/or a surfactant.Exemplary mucolytics and surfactants are saline, acetylcystein,ambroxol, carbocystein, tyloxapol, dipalmytoylphosphatidylcholin,recombinant surfactant proteins, and DNase. In one embodiment, the yetadditional therapeutic agent is an antibiotic agent. Exemplaryantibiotics are beta-lactam antibiotics, including amoxycillin,piperacillin, cephalosporines, including cefaclor, cefazedon, cefuroxim,cefoxitin, cefodizim, cefsulodin, cefpodixim, and cefixim, carbapenemessuch as imipenem and cilastatin, monbactames, such as, aztrenonam,aminoglycosides, including streptomycin, neomycin, paromomycin,kanamycin, gentamycin, amicacin, tobramycin, and spectinomycine,tetracyclines, such as doxycyclin and minocycline, macrolides includingerythromycine, clarithromycine, roxithromycine, azithromycin,josamycine, and spiramycine, gyrase inhibitors or quinolones such asciprofloxacin, ofloxacine, levofloxacine, pefloxacine, lomefloxacine,fleroxacine, clinafloxacine, sitafloxacine, gemifloxacine,balofloxacine, trovafloxacine, and moxifloxacine, sulfonamides andnitroimidazoles (including metronidazol, tinidazol), chloramphenicol,lincomycine, clindamycine, and fosfomycine, and glycopeptides such asVancomycine and Teicoplanine. In yet additional embodiments, theadditional therapeutic agent is an anti-inflammatory drug. Exemplaryanti-inflammatory drugs include ibuprofen, dornase alfa, BIIL 284,ajulemic acid, a PDE4 inhibitor (e.g., roflumilast), romoglycate andnedocromil. In yet additional aspects, the additional therapeutic agentis azithromycin. In an additional aspect, acebilustat is co-administeredwith a corticosteroid. Exemplary corticosteroids are beclomethasone,betamethasone, budesonide, ciclesonide, flunisolide, fluticasone,icomethasone, mometasone, rofleponide, and triamcinolone. In yet furtheraspects, the additional therapeutic agent is bradykinin, prostaglandin,leukotriene and platelet activating factor antagonists. The inventionencompasses administration of one or more additional therapeutic agents,or a combination thereof concomitantly with acebilustat. In certainadditional aspects, the invention encompasses administration of one ormore additional therapeutic agents, or a combination thereofconcomitantly with acebilustat to a cystic fibrosis patient.

The invention is illustrated by the following non-limiting examples.

Example 1: EMPIRE-CF: A Phase II Randomized Placebo-Controlled Trial ofOnce-Daily, Oral Acebilustat in Adult Patients with CysticFibrosis—Study Design, Patient Demographics and Results

Acebilustat is a novel, synthetic, small-molecule leukotriene A4hydrolase inhibitor in development as a once-daily oral therapy thatmodulates LTB4 production and targets the inflammatory process in CF[Elborn et al., 2017a]. In two Phase I trials, acebilustat reduced LTB4production and other inflammatory markers in healthy volunteers andpatients with CF [Elborn et al., 2017a, Elborn et al., 2017b]. Based onthese promising data, a Phase IIb study, EMPIRE CF (Evaluation of themodulation of the pulmonary inflammatory response in CF) was designedand completed to determine the dose, duration and endpoints for futureclinical trial(s). The study was the first proof-of-concept for a novelanti-inflammatory therapy designed to show prevention of progressiveloss of lung function and/or reduction of pulmonary exacerbations in CFpatients. Described below is the study design, rationale, and results.The demographics of the study population are also presented, and theirimportance to the study outcomes is discussed.

Methods Design Considerations

Previous short-term trials (12 weeks' treatment or less) have shown thatanti-inflammatory medications may not lead to acute changes in forcedexpiratory volume in one second percent predicted (FEV₁pp) or evenchanges in biomarkers of inflammation, despite the potential foreffective therapy [Elborn et al., 2012; Moss et al., 2013; Chmiel etal., 2015]. A longer-term study is more likely to show attenuation inthe annual rate of lung function decline, as well as reductions inexacerbations. For example, the four-year high-dose ibuprofen studydemonstrated a decreased rate of FEV₁ decline in a general CFpopulation, without demonstrating more rapid evidence of benefit.[Konstan et al., 1995]. Such a duration is not feasible for currentPhase II trials. On this basis, a treatment period of 48 weeks wasconsidered for the current study, with a larger sample size to detectchanges over a shorter period of observation (see section below).

Measuring significant changes in lung function decline and exacerbationfrequency is only possible if the correct patient population isenrolled. We hypothesized that certain subsets of the general CFpopulation may be at greater risk for rapid lung function decline, andthat this subset may provide a study population that is affected byactive inflammation, and that also experiences a decline of adequatemagnitude to detect clinical benefit over a 48-week interval. Such asubset was identified through research of the Cystic Fibrosis PatientRegistry (CFPR) and based on knowledge of the projected rate of declineof FEV₁pp and the frequency of pulmonary exacerbations in thissubpopulation. For example, prior pulmonary exacerbations are one of thestrongest predictors of a future pulmonary exacerbation [Block et al.,2006; VanDevanter et al., 2016]. Furthermore, it has been estimated thatup to half of lung function decline is related to pulmonaryexacerbations [Waters et al., 2012] and that exacerbations are a clearindicator of active neutrophil driven inflammation. Susceptibility toannual decline in lung function is greatest from adolescence to earlyadulthood and attenuates after patients reach approximately 30 years ofage [Liou et al., 2010]. Additionally, patients with a higher baselinelung function may also be more susceptible to greater declines in FEV₁pp[Konstan et al., 2012].

Based on these published observations, data from the CFPR (CysticFibrosis Foundation, 2014) were analyzed for different age ranges (12-17years, 18-30 years, 31-35 years, or 36-39 years); baseline FEV₁pp(50-59%, 60-79%, 80-99%, or ≥100%) and number of pulmonary exacerbationsrequiring use of an IV antibiotic in the prior year (0 or ≥1). Theregistry data provided strong support for the concept that patients12-30 years old who had had at least one pulmonary exacerbation in theprior year were at highest risk for rapid lung function decline. Withinthis subgroup, the registry data provided further evidence that patientswith a higher FEV₁pp at baseline were likely to have the most rapiddecline in FEV₁pp. Within the subgroup of 18-30 years' old CF patientswho had had at least one pulmonary exacerbation in the prior year, thepresent year rate of decline is estimated to be 3.47 percentage pointsper year. Detection of differences in rate of FEV₁pp decline versusplacebo on the order of 3 percentage points per year requiresobservation over at least 48 weeks. Thus, the patient population for thecurrent study was enriched based on optimal patient age, FEV₁pp andexacerbation history, in order to detect versus placebo a difference inrate of FEV₁ decline and difference in exacerbation rate over 48 weeksin a Phase II study (see section 2.4). This population and studyduration is in line with published guidance from the Cystic FibrosisFoundation (CFF) [Torphy et al., 2015].

This Phase II study was used as an important test of the study designwhile also establishing proof of concept that leukotriene A4 hydrolase(LTA₄H) is a therapeutic target in CF. A priori baseline stratificationbased on lung function (as FEV₁pp), number of exacerbations in the prioryear, and concomitant CFTR modulator use ensured that patientcharacteristics were balanced between treatment arms to allowidentification of the optimal patient population for future trials. Theinclusion of CFTR modulator use as a stratification criterion is alsoimportant given the evolving standard of care, which may soon includeuse of a CFTR modulator regimen across a broad spectrum of the CFpopulation.

Overall Study Design

EMPIRE-CF was a Phase II multicenter, randomized, double-blind,placebo-controlled, parallel-group study to evaluate the efficacy andsafety of acebilustat in adult patients with CF (NCT02443688). The studyconsisted of a 48-week treatment period and follow-up visit 4 weeksafter treatment completion. Screening visits occurred up to 21 daysprior to the first study drug dose (FIG. 2).

Patients

Patients were enrolled from 69 centers in the USA, Canada, and Europe.All centers were experienced in CF care and the conduct of clinicaltrials. Inclusion and exclusion criteria are shown in Table 2. In brief,adult women and men 18-30 years old with a documented diagnosis of CF,an FEV₁pp≥50% at screening and at least one pulmonary exacerbation inthe previous year were enrolled. Baseline demographics are presented inthe section below.

Altogether, 284 patients were screened, 200 patients enrolled, and 199patients (the FAP) received at least one dose of study drug (acebilustat100 mg, n=66; acebilustat 50 mg, n=67; placebo, n=66); one patient inthe placebo group was randomized but discontinued before receiving thestudy drug. Overall, 32 patients (16%) discontinued the study before theWeek 48 visit, including 21 (15.8%) from the acebilustat treatmentgroups and 11 (16.7%) from the placebo group. The most common reasonsfor discontinuation were withdrawal of informed consent (5%) andnoncompliance with study drug (3%). The per-protocol (PP) analysisincluded 162 patients (acebilustat 100 mg, n=54; acebilustat 50 mg,n=54; placebo, n=54). Mean compliance with study drug was 93% in theacebilustat 100 mg group, 96% in the acebilustat 50 mg group, and 96% inthe placebo group.

Interventions

Patients were randomized 1:1:1 to receive either once-daily oralacebilustat 50 mg or 100 mg (Celtaxsys, Atlanta, Ga., USA), or placebosupplied as capsules. The two acebilustat doses were selected based onthe levels of reduction of serum LTB4 production seen in Phase Istudies. The 100 mg dose resulted in near-maximum LTB4 reduction (86%reduction) whilst the 50 mg dose showed a peak reduction in LTB4production of ˜75% [Elborn et al., 2017b].

Outcomes

The primary endpoints were absolute change from baseline in FEV₁pp andsafety outcomes. Secondary endpoints included rate of pulmonaryexacerbations and time to first pulmonary exacerbation, and the effectson biomarkers of lung and systemic inflammation. Analyses are describedin section entitled “Analysis.”

Pulmonary exacerbations were defined as the requirement for oral,inhaled or intravenous antibiotics for four or more signs or symptomsaccording to the modified Fuch's criteria (change in sputum; new orincreased hemoptysis; increased cough; increased dyspnea; malaise,fatigue or lethargy; temperature >38° C.; anorexia or weight loss; sinuspain or tenderness; change in sinus discharge; change in physicalexamination of the chest; ≥10% absolute decrease in FEV₁pp from thepreviously recorded value; radiographic changes indicative of pulmonaryinfection) [Fuchs et al., 1994], referred collectively (antibiotics plusthe four or more signs and symptoms) as expanded Fuchs criteria. Thedate the pulmonary exacerbation began was defined as the first day ofantibiotic use.

Assessments

Patient Medical Status

At the screening visit, investigators recorded a full medical historyand performed a complete physical examination and laboratory tests todetermine eligibility for the study. At the screening visit,demographics and disease characteristics, concomitant CF medications(including use of CFTR modulators such as ivacaftor or lumacaftor, useof dornase alfa and chronic azithromycin), history of Pseudomonasaeruginosa colonization and CFTR genotype were recorded. The number ofpulmonary exacerbations in the last 12 months and the date of lastpulmonary exacerbation were also recorded at screening.

Spirometry

Spirometry data were recorded at screening and baseline; all otherspirometric measurements at subsequent visits are ideally recordedwithin 1 h of the baseline visit measurement. All tests met AmericanThoracic Society/European Respiratory Society criteria for quality(acceptability, reproducibility, and end of test criteria) [Miller etal., 2005]. To ensure consistency of measurement, spirometrymeasurements were ideally performed by the same researcher and thepatient coached to use maximum effort at every attempt. Patients wereable to take all of their concomitant medications according to theirregular schedule; however, they were to refrain from using short-actingbronchodilators within 4 h of the scheduled spirometry time, andlong-acting bronchodilators within 12-24 h of the scheduled spirometrytime.

Safety

Treatment-emergent adverse events (TEAEs), including serious adverseevents, were collected at each visit, and summarized by MEDRA systemorgan class and preferred term, severity, and relatedness to the studydrug. An independent data monitoring committee monitored the safety andstudy conduct at approximately 8-week intervals.

Treatment Adherence

Assessments of adherence to treatment with the study drug were based ona capsule count by investigators at visits 3, 5-9, 11, 13, and 15.Patients were asked whether any capsules had been lost or destroyed toensure accuracy of the adherence assessment.

Sample Size Determination

It was assumed that a sample size of 156 patients in the full analysispopulation (FAP, n=52 acebilustat 50 mg: n=52 acebilustat 100 mg: n=52placebo) would be required for the primary endpoint. However, to ensurean adequate sample size for a per-protocol (PP) analysis (based on 80%of patients being included in the PP population), the number ofrandomized patients in the FAP was 195, i.e. n=65 in each treatment arm.

Sample size calculations were based on the primary efficacy endpoint ofan absolute change from baseline in FEV₁pp. Assumptions in thecalculation are that: there is a 1:1:1 ratio of patients receiving 50 mgacebilustat vs 100 mg acebilustat vs placebo; the difference in averagetreatment effect for active treatment (both doses of acebilustat) vsplacebo is at least 3.5 units at 48 weeks. With a standard deviation of7 units the study had a power of at least 90% with one-sided alpha of0.05 to detect the difference in average treatment effect (change frombaseline in FEV₁pp) for active treatment (both doses of acebilustat) vsplacebo of 3.5 units at 48 weeks.

Randomization and Blinding

Eligible patients were randomized to active treatment by an interactiveweb-based randomization system (IWRS). Randomization was stratified bybaseline FEV₁pp (50 to 75% and >75%), number of pulmonary exacerbationsin the 12 months before screening (1 or >1) and use of CFTR-modulatingtherapy ivacaftor or ivacaftor+lumacaftor (yes/no). All patients,investigators and others in direct contact with patients were blinded totreatment assignment as were the sponsor and contract researchorganization staff.

Analysis

Primary Endpoint

The primary analysis was based upon an analysis of variance (ANOVA) inwhich the average of the Week 48 change from baseline in FEV₁pp for thetwo acebilustat doses was compared to that in the placebo group. TheANOVA model contained a separate term for each dose group with theaverage over the two acebilustat doses created by averaging theparameter estimates from the ANOVA model. In addition to terms fortreatment group, the ANOVA included stratification for the factors usedfor randomization. If the primary analysis (aggregate acebilustateffect) reached the 0.05 level of significance (one-sided), theindividual acebilustat doses would be compared to the placebo arm usingDunnett's procedure at the 0.05 (two-sided) alpha level.

Secondary Endpoints

Pulmonary exacerbations were analyzed both as the time to firstpulmonary exacerbation and the rate of pulmonary exacerbations. The timeto first protocol defined-pulmonary exacerbation were analyzed using aCox proportional hazards model. The number of protocol-defined pulmonaryexacerbations reported through the Week 48/Early Termination visit wereannualized (where a year was defined as 52 weeks) analyzed using anegative binomial regression. The two active doses were compared toplacebo individually as well as pooled together using a contraststatement similar to that used for the primary analysis. Pointestimates, standard errors, and 95% CIs for the mean of number ofpulmonary exacerbations were presented. The difference in means betweeneach CTX-4430 group from placebo were presented along with standarderrors and 95% CIs. Spirometry-based endpoints were analyzed using thesame methods as the primary endpoint. Analyses of sputum DNA andelastase and serum high-sensitivity C-reactive protein were based upondescriptive statistics by treatment group.

Exploratory Endpoints

Analyses of sputum bacterial density (total and that for P. aeruginosa,Burkholderia cepacia complex, Achromobacter xylosoxidans,Stenotrophomonas maltophilia, and Staphylococcus aureus [includingmethicillin-resistant S. aureus and small colony variants of S. aureus)]and health-related quality of life (using the Cystic FibrosisQuestionnaire-Revised (CFQ-R) quality-of-life measure [Quittner et al.,2000]) were based upon descriptive statistics by treatment group.

Baseline Characteristics

A total of 200 patients were enrolled in the study. Patients had a meanage of 23.7 years, and mean FEV₁pp of 70.6% overall at baseline. Nearlyone-third of patients were using concomitant CFTR modulators. The meannumber of exacerbations in the prior year was 2. Nearly half of allpatients had experienced one exacerbation in the prior year; while 28.5%experienced two, and 25% three or more exacerbations.

Results

In this Phase IIb study, cystic fibrosis (CF) patients were enrolledinto one of three treatment arms: placebo, 50 mg acebilustat, or 100 mgacebilustat (FIG. 2). The patients were pre-stratified across thetreatment arms by three criteria: baseline lung function (as measured byFEV1 percent predicted, FEV1pp), the number of pulmonary exacerbationsin the year prior to enrollment, and the use of concomitant treatmentwith CFTR modulator therapies. Enrolled patients were followed through48 weeks of treatment and an additional 4 weeks post-treatment. Duringthe course of the study, patients were monitored for changes in lungfunction and occurrence of pulmonary exacerbations in order to assesstreatment effects.

Pulmonary exacerbations were an important secondary endpoint, sinceanti-inflammatory therapies are expected to demonstrate benefit inpulmonary exacerbations as compared to changes in spirometry, althoughthis Phase 2 study was not powered to detect statistically significantchanges in pulmonary exacerbations. The annual rate of pulmonaryexacerbations was calculated by standard methods for each treatmentgroup. Two main overall populations were examined: a Full AnalysisPopulation (FAP), which consisted of any patient taking at least onedose of treatment, and a Per Protocol Population (PP), which consistedof patients meeting all inclusion/exclusion criteria and compliant withat least 80% of their treatment regimen and who also had an assessmentat week 48.

In the FAP, the adjusted mean (95% CI) annualized pulmonary exacerbationrates based on the negative binomial regression model were 1.51 (1.26,1.81) in the combined acebilustat groups, 1.57 (1.22, 2.02) in the 100mg dose group and 1.46 (1.13, 1.89) in the 50 mg dose group), and 1.56(1.21, 2.01) in the placebo group (FIG. 3A). The time to first pulmonaryexacerbation was numerically greater in patients receiving acebilustat(combined and individual dose groups) versus placebo. The hazard ratiosversus placebo (95% CI) were 0.87 (0.605, 1.246) in the acebilustatcombined group, 0.88 (0.576, 1.339) in the acebilustat 100 mg group, and0.86 (0.563, 1.308) in the acebilustat 50 mg group (FIG. 4A). Theproportion of patients who did not experience a pulmonary exacerbationduring the study period was also numerically greater in the acebilustatgroups (51 of 133 patients [38%] in the combined acebilustat dose group,25 of 66 patients [38%] in the 100 mg dose group, and 26 of 67 patients[39%] in the 50 mg group) than in the placebo group (20 of 66 patients[30%]) (FIGS. 5A and 6A). In the PP analysis, the difference in the rateof pulmonary exacerbations in the acebilustat group versus placebo wasgreater than the FAP (FIG. 3B). The time to first pulmonary exacerbationand the proportion of patients who did not experience a pulmonaryexacerbation during the study was also numerically higher (FIGS. 4A, 4B,5A, 5B, 6A and 6B). In the FAP and PP analysis, the divergence inpulmonary exacerbation from placebo occurred at approximately 4 months.

Kaplan-Meier analysis was conducted based on the fraction of patientsremaining exacerbation free as a function of time (FIGS. 4A and 4B). Thecurves for the treated groups diverged from the placebo curve indicatingan increased time to first exacerbation for both dose groups in both theFAP and PP (FIGS. 4A and 4B, respectively). At 48 weeks, the hazardratios for risk of exacerbation indicate a treatment effect for bothacebilustat dose groups in reduced risk of exacerbation compared toplacebo. In addition, the number of patients who did not experience apulmonary exacerbation over the course of the 48 weeks of treatment wasdetermined for each treatment group. This analysis indicates a largerproportion of patients treated with acebilustat remainedexacerbation-free in both the FAP (FIGS. 5A and 6A) and PP (FIGS. 5B and6B).

In a prespecified analysis, CF patients in the study were groupedaccording to their baseline lung function being above or below themedian FEV1pp for the entire study population, which was found to be68%. Patients with milder lung disease, those with baseline FEV1pphigher than the median (>68%), were found to respond to acebilustattreatment as evidenced by a lower annual rate of pulmonary exacerbationsversus placebo (FIG. 7B). In contrast, patients with baseline FEV1pp ator below the median (≤68%) did not exhibit the same level of response toacebilustat treatment (FIG. 7A).

In a prespecified analysis, CF patients in the study were groupedaccording to their baseline lung function (FEV1pp 50-75, or >75%).Patients with milder lung disease (baseline FEV1pp>75%), were found torespond to acebilustat treatment as evidenced by a lower annual rate ofpulmonary exacerbations in both the FAP and PP (FIGS. 8A and 8B,respectively). Specifically, the mean annualized rate of pulmonaryexacerbation in patients with baseline FEV1pp>75% was lower by about 35%in the combined acebilustat dose groups versus placebo; this differencewas greater than in the overall study population. The adjusted mean (95%CI) annualized rate of pulmonary exacerbations in this pre-specified FAPpopulation was 1.04 (0.74, 1.46) in the combined acebilustat groups,0.84 (0.49, 1.44) in the 100 mg dose group, and 1.28 (0.84, 1.96) in the50 mg dose group versus 1.61 (1.07, 2.42) in the placebo group (FIG.9A). The effect of acebilustat versus placebo on time to first pulmonaryexacerbation was also more pronounced in this population than in theoverall trial population. Hazard ratios (95% CI) versus placebo were0.57 (0.307, 1.051) in the acebilustat combined group, 0.52 (0.245,1.101) in the acebilustat 100 mg group, and 0.62 (0.304, 1.274) in theacebilustat 50 mg group for the FAP (FIG. 9A). Almost half of thepatients with mild disease receiving acebilustat did not have apulmonary exacerbation during the study (23 of 47 patients [49%] in thecombined acebilustat group; 11 of 22 patients [50%] in the 100 mgacebilustat group; 12 of 25 patients [48%] in the 50-mg acebilustatgroup), while only 6 of 24 patients (25%) in the placebo group did nothave a pulmonary exacerbation (FIG. 11, 17A, 18A). The exacerbation ratedata for subjects with baseline FEV1pp≤75% is shown in Table 1 below.These patients did show a numerical benefit in the rate of exacerbationsversus placebo but the difference was less pronounced. In contrast topatients with baseline FEV1pp above 75% (FIG. 9A), those patients withFEV1 at or below 75% (≤75%) did not exhibit the same level of responseto acebilustat treatment (FIG. 9B). This is evidenced by both a reducedannual rate of exacerbations and a reduced hazard ratio for time tofirst exacerbation in the population with baseline FEV1pp>75% (FIG. 9A)as compared to an unchanged or increased rate and hazard ratio in thepopulation with FEV1pp at or below 75% (≤75%) (FIG. 9B). Kaplan-Meieranalysis of the population of CF patients with baseline FEV1pp>75%indicated a prolonged time to first exacerbation and a reduced hazardratio for risk of exacerbation compared to placebo for both acebilustatdose groups in both FAP and PP (FIGS. 10A and 10B, respectively). Inaddition, more patients treated with acebilustat in the group havingbaseline FEV1pp>75% remained free from pulmonary exacerbation during the48 weeks of treatment compared to those in the placebo group (FIG. 11).

FIGS. 15A and 15B show the effect of acebilustat on pulmonaryexacerbation rate in patients having baseline FEV1pp>70, which is the CFcommunity standard definition of “mild” CF disease, compared to patientshaving baseline FEV1pp>75 (the prespecified definition of “mild” CF usedin the clinical study). As shown in the figure, acebilustat demonstratesa substantial reduction in pulmonary exacerbations in both groups withvarying definitions of “mild” CF disease.

In summary, the therapeutic effect of acebilustat in reducing pulmonaryexacerbations is greatest in CF patients with the higher FEV1pp atbaseline (“mild CF disease”). Table 1 shows that both the 50 mg and 100mg doses showed therapeutic benefit in patients with a baseline FEV1ppof 65% or greater, with the greatest benefit seen at baseline ppFEV1above 70%. The 100 mg dose of acebilustat also showed therapeuticbenefit at baseline FEV1pp of greater than 60%. The terms “FEV1pp” and“ppFEV1” are used interchangeably.

TABLE 1 Annualized Rate of Pulmonary Exacerbation (Adjusted Mean)Acebilustat 100 mg Acebilustat % 50 mg difference % differenceAcebilustat from Acebilustat from Subgroup 100 mg Placebo 500 mg PlaceboPlacebo Baseline 1.27 −14% 1.44  −2% 1.47 ppFEV₁ >60 Baseline 1.05 −28%1.25 −14% 1.45 ppFEV₁ >65 Baseline 0.81 −33% 1.12  −7% 1.21 ppFEV₁ >68Baseline 0.92 −40% 1.2  −22% 1.54 ppFEV₁ >70 Baseline 0.84 −48% 1.28−20% 1.61 ppFEV₁ >75

In addition, patients taking acebilustat alongside concomitant treatmentwith CFTR-modulator therapies exhibited a reduced annual rate ofpulmonary exacerbations and a reduced hazard ratio for risk ofexacerbation compared to patients taking placebo alongside concomitantCFTR-targeted therapy (FIGS. 12A and 12B). These effects were evidentfor both acebilustat doses in both the FAP and PP populations (FIGS. 12Aand 12B, respectively). Additionally, the proportion of exacerbationfree CF patients taking acebilustat with concomitant treatment withCFTR-modulator therapy was lower compared to patients taking placebowith concomitant CFTR-targeted therapy (FIGS. 13A and 13B). This effectpersisted until the end of the 48 weeks of treatment and was evident forboth acebilustat doses in both the FAP and PP populations (FIGS. 13A and13B, respectively).

As shown in FIGS. 16A and 16B, acebilustat treated patients had a lowerpulmonary exacerbation rate in CF patients with mild disease (FEV1pp>75)whether taking (“on”) or not taking (“off”) concomitant CFTR modulatortherapy. The greatest effect of acebilustat on pulmonary exacerbationsin the entire study (65% lower versus placebo for the 100 mg dose) wasobserved in patients with mild disease concomitantly treated with CFTRmodulator therapies (FIG. 16A), suggesting the potential for mechanisticsynergy. For the data shown in FIGS. 16A and 16B, the correspondingplacebo groups were matched with the acebilustat treatment groups inregard to CFTR modulator use, i.e., for the patients “on” CFTRmodulator, patients taking acebilustat plus CFTR modulator were comparedto those taking CFTR modulator alone.

As shown in FIGS. 17A to 17C, acebilustat treated patients had a higherproportion (versus placebo) of patients free from pulmonaryexacerbations during the course of the 48 weeks of treatment in thetotal study population (FIG. 17A) as well as in mild CF patients whethertaking (“on”) (FIG. 17B) or not taking (“off”) (FIG. 17C) concomitantCFTR modulator therapy. Surprisingly, and consistent with the effect onpulmonary exacerbation rate, the effect of acebilustat in increasing thepercentage of exacerbation-free patients was greatest in patients takingconcomitant CFTR modulator therapy (see FIG. 17B).

FIGS. 18A and 18B shows that both the 100 mg and 50 mg dose ofacebilustat had a higher percentage of exacerbation-free patients in themild (FEV1pp>75%) subgroup. FIGS. 20 and 21 show that the 100 mg dose ofacebilustat had a lower rate of pulmonary exacerbations requiringhospitalization and a lower the rate of pulmonary exacerbationsrequiring intravenous antibiotics as compared to placebo.

FIGS. 19A and 19B show the effect acebilustat (100 mg in the mildpopulation) and CFTR modulator therapies (KALYDECO®, SYMDEKO®, andORKAMBI®) on percent differences from placebo in rate of pulmonaryexacerbations and risk of pulmonary exacerbations, respectively. Thesefigures show that the magnitude of effect of acebilustat (100 mg dose)in the mild CF population in terms of benefit in both annual rate andrisk of pulmonary exacerbations was similar or better than that observedfor recently approved CFTR modulator therapies (at approved doses) intheir respective genetically-targeted populations. Even though this isdata from different studies, this confirms that the level of effect seenfor acebilustat in terms of pulmonary exacerbations is consideredtherapeutically meaningful.

In summary, the major effect of acebilustat is a reduction in the rateof pulmonary exacerbations (PEx) and reduced risk of progression topulmonary exacerbations. In the study, acebilustat demonstratedclinically meaningful improvements in pulmonary exacerbations, bothreducing the frequency of pulmonary exacerbations (PEx) and increasingtime to next exacerbation over 48 weeks of therapy. Patients in keyprospectively-identified sub-groups, including those with mild CF lungdisease at baseline and/or taking concomitant CFTR modulator therapy,derived the most benefit. The benefit, when used in combination with aCFTR modulator, is an important consideration given the likelihood of anincrease in number of CF patients who are eligible to be treated withCFTR modulators over the coming years. This addresses the unmet need toreduce lung inflammation, that persists despite CFTR modulator therapy,adequately for the optimal treatment of patients with cystic fibrosis.Acebilustat-treated patients exhibited an 18% reduction in PEx and a 22%reduced risk in progressing to first PEx versus placebo. Additionally,compared with placebo, 32% more patients treated with acebilustat had noPEx during the study. The benefits of acebilustat on pulmonaryexacerbations were apparent as early as four months after start oftreatment and persisted throughout the 48 weeks of the study. Lungfunction, as measured by FEV1 percent predicted (FEV1pp), inacebilustat-treated patients was not different from placebo over 48weeks of therapy. Previous research with CFTR modulators have shownthat, on an individual patient basis, FEV1pp response does not alwayscorrelate with PEx response.

Patients with less severe impairment of lung function (FEV1pp>75)achieved the largest benefit from acebilustat therapy, achieving a 34%reduction in PEx rate, a 43% reduction in risk of experiencing theirfirst exacerbation and a 96% increased likelihood of being exacerbationfree after 48 weeks of treatment. Furthermore, patients concomitantlytreated with CFTR modulator therapy exhibited a clinically meaningful18% reduction in PEx, a 29% increased time to first exacerbation and a47% higher likelihood of no exacerbations compared to patients treatedwith CFTR modulators and placebo. Acebilustat was well tolerated with noincreased risk of infection, a key attribute for any anti-inflammatorydevelopment candidate to treat CF patients who have an increased risk ofinfection. The majority of adverse events were mild or moderate inseverity. There was a low discontinuation rate from adverse events.

Patients treated with acebilustat exhibited a slight FEV1pp improvementbut did not separate from placebo on the primary endpoint. Specifically,FEV1pp had wide variability and was not predictive of decreasedpulmonary exacerbation (PEx responders). This study provides evidencethat decrease in pulmonary exacerbations is a better outcome measurementfrom anti-inflammatory therapy than FEV1pp.

DISCUSSION

The damaging impact of chronic inflammation is well recognized in CF.Although CFTR mutations have been implicated in some aspects ofinflammation [Rubin 2007; Perez et al., 2007], CFTR modulators do notfully address chronic lung inflammation [Rowe et al., 2014], makingtreatments in this area a significant unmet need [Torphy et al., 2015].

The LTA4 inhibitor acebilustat is in development as an anti-inflammatorytherapy in CF and has shown promising results in Phase I studies. In astudy of once-daily acebilustat in adult patients with CF, the drugsignificantly reduced sputum neutrophil levels by up to 65% and sputumelastase levels by up to 58%. Numerical reductions in C-reactive proteinwere observed in the acebilustat treated groups [Elborn et al., 2017a].Sputum LTB4 levels decreased significantly in acebilustat-vsplacebo-treated patients [Elborn et al., 2017b]. These Phase I studieshighlighted several important PK/PD aspects of acebilustat. Dataconfirmed that once-daily oral dosing is appropriate [Elborn et al.,2017b]. No significant differences occurred between healthy volunteersand patients with CF in the C_(max) or AUC₀₋₂₄ of acebilustat. Given thehigh burden of CF therapies [Harman et al., 2017], a simple dosingregimen for any additional therapies is important. Furthermore, nodifferences occurred in the AUC₀₋₂₄ at steady state in fed vs fastingpatients [Elborn et al., 2017b]. This is relevant given the potentialfor compromised absorption from the gut in patients with CF and theircomplex dietary needs [Li and Somerset 2014]. Additionally, acebilustatdid not induce CYP3A4, a known metabolizer of the CFTR modulatorivacaftor and, importantly, these data show that the two drugs(acebilustat and ivacaftor) could be taken concomitantly [Elborn et al.,2017b]. The adverse event profile of acebilustat was closely monitoredin the Phase I studies. Reassuringly, acebilustat was well tolerated inthese trials. The majority of treatment-emergent adverse events (AEs)were mild or moderate in severity and no drug-related serious AEsoccurred in these studies [Elborn et al., 2017a, b].

The promising data from the Phase I studies led to the progression ofacebilustat into the Phase IIb trial described here. The trial has beenrobustly designed, taking into account guidance from the CFF, includingrecommendations from the 2014 CFF Anti-inflammatory Strategy Group(CFF-ASG) [Torphy et al., 2015]. The study endpoints examined bothchange from baseline in lung function and pulmonary exacerbations, bothof which have real-life clinical impacts. Lung function decline is apowerful predictor of morbidity [Kerem et al., 1992], while pulmonaryexacerbations are associated with a non-recoverable loss in lungfunction and decline in health status in many patients [Sanders et al.,2010].

Choosing a study duration appropriate to the drug being tested isimportant. While CFTR modulators can lead to a relatively rapidimprovement in lung function [Rowe et al., 2014], longer-term trials arerequired to show benefits from anti-inflammatory therapies that aim tostem the decline in lung function and/or decreasing pulmonaryexacerbation rate. The CFF-ASG recommended that trials Phase II shouldbe at least 3-6 months [Torphy et al., 2015], but for more conclusivedata on anti-inflammatory effects, a 12-month study may be preferred.The current study had a 48-week treatment period.

Enrolling the most appropriate patient phenotype is key to assessingclinical outcomes in a trial for a novel potential therapy. Patients forEMPIRE-CF were selected based on stringent inclusion criteria (age 18-30years, FEV₁pp>50, and at least one exacerbation in the past year). Thisenriched the study population with patients who are most susceptible topulmonary exacerbations and annual lung function decline. The enrolledpatients experienced a mean of 2.1 exacerbations in the prior year.Modelling FEV₁pp decline from a similar patient group in the CFPR(Cystic Fibrosis Foundation, 2015) suggests that patients eligible forthis study may have an annual decline in FEV₁pp of 3.5 (standarddeviation [SD] 7.9), ranging from 2.7 (SD 7.6) for those with oneexacerbation in the year prior, to 3.7 (SD 7.9) for those with 2, and5.1 (SD 8.4) for those with ≥3 [Elborn et al., 2018]. Importantly, thetotal trial population size was calculated to ensure that the trial wassufficiently powered to show a difference in lung function decline fromplacebo. With trial population size and trial duration, there was alsothe potential that a benefit in pulmonary exacerbations may bedetectable in this population.

Ensuring treatment arms were well balanced with respect to patientcharacteristics would help identify any specific patient groups that aremore likely to benefit from acebilustat and who could be included infuture clinical trials. Randomization was, therefore, stratified bybaseline FEV₁pp, number of pulmonary exacerbations in the prior 12months, and use of CFTR-modulating therapy. Stratification based onconcomitant CFTR modulator use is important as neutrophil elastase isshown to downregulate CFTR [Le Gars, et al. 2013]; an anti-inflammatoryagent, such as acebilustat, that reduces neutrophil elastase could havesynergistic effects with CFTR modulators.

It was expected that the unique and rigorous design elements of theEMPIRE-CF trial would help identify the optimal patient population,dose, duration and endpoints for future trials, and widen ourunderstanding of the efficacy of acebilustat in patients with CF. Thepresent study provides evidence that pulmonary exacerbation is a betteroutcome measure for anti-inflammatory therapy such as acebilustat thanchange in FEV₁pp. No difference between acebilustat and placebo wasobserved for the primary endpoint, absolute change in ppFEV₁ frombaseline at Week 48.-Given the mechanism of action of acebilustat as ananti-inflammatory agent, and prior experience with ibuprofen [Konstan etal. 1995], an acute increase from baseline in ppFEV₁ signifying abronchodilatory or mucociliary clearance effect would not be expected.Additionally, to demonstrate a reduction in decline of lung functionversus placebo would likely have required a longer trial as was the casewith the 4-year high dose ibuprofen study [Konstan et al. 1995].

Importantly, analyses of the secondary endpoints showed that acebilustattreatment led to a numerical decrease in rate of pulmonaryexacerbations, an increase in the time to first pulmonary exacerbation,and a higher proportion of patients with no pulmonary exacerbations.These differences from placebo were numerical but were internallyconsistent across several measures of exacerbations. These effects wereparticularly evident in patients who had milder disease (ppFEV₁>75% atbaseline), consistent with previous findings that high dose ibuprofentreatment in children resulted in a lower rate of FEV1 decline andimproved survival in children with evidence of advancing lung disease(ppFEV₁<100) but still in the milder population (ppFEV₁≥60) whereasthere was no survival benefit observed in children with advanced lungdisease (ppFEV₁<60) [Konstan et al. 2018]. In addition, the magnitude ofthe effect of acebilustat on pulmonary exacerbations was also moreprominent in those using concomitant CFTR modulators, a group that maymore closely resemble those with milder CF lung disease due to partialrestoration of CFTR activity.

Although CFTR modulators have been shown to reduce the rate of lungfunction decline, they have not consistently shown an impact on markersof airway inflammation, and patients receiving CFTR modulator treatmentstill experience exacerbations and progressive loss of lung function[Sawicki et al. 2015; Konstan et al. 2017; Hisert et al. 2017; Rowe etal. 2014]. Our study findings suggest that the addition of acebilustatto CFTR modulator therapy may further reduce pulmonary exacerbations andpotentially further reduce long-term loss of lung function. Trials oflonger duration are needed to detect the effect of combination treatmenton the trajectory of lung function decline.

Reducing pulmonary exacerbations is a critical goal of CF therapy, asexacerbations are associated with significant morbidity, decline in lungfunction, and early death [de Boer et al. (2011); Konstan et al. 2012;Stephenson et al. 2015]. The findings of the present study indicate thattargeting neutrophil-mediated inflammation in CF with acebilustat couldhave clinical benefits by reducing pulmonary exacerbations, particularlyin the context of concomitant CFTR modulator treatment, and in patientswith mild lung disease. This approach warrants further investigation inthese populations.

Direct targeting of LTB₄ inflammatory signaling was investigated in aclinical trial of amelubant (BIIL 284), an antagonist of the BLT1receptor, but this trial in patients with stable CF lung disease wasterminated early due to an increase in serious pulmonary AEs [Konstan etal. 2014]. Amelubant, at the doses used in the study, may have had anoverly potent effect on the BLT1 receptor, impairing antibacterialdefenses, and permitting increased infection [Chmiel et al. 2007; Dorinet al. 2014]. Its mechanism as a receptor antagonist may also haveresulted in increased LTB₄ presence in the airways as a deleteriousconsequence. As acebilustat acts to reduce LTB₄ synthesis by inhibitingthe LTA4H enzyme, it is likely to downregulate signaling through theBLT1 receptor rather than block signaling. This is reflected in theacceptable safety profile observed for acebilustat in this study whereacebilustat was safe and well tolerated in patients with CF. Most AEswere either mild or moderate in intensity and considered by theinvestigator to be unrelated or unlikely to be related to study drug.There were few discontinuations due to AEs.

Neutrophil elastase is a key marker of inflammation associated with lungfunction decline in patients with CF [Mayer et al. (2007)]. In a phase 1trial of acebilustat, sputum levels of neutrophil elastase, as well assputum neutrophil DNA and serum high-sensitivity C-reactive protein,were reduced with acebilustat treatment compared with placebo [Elborn etal. (2017)]. We did not observe similar changes in this study. Thisfinding may be due to limitations related to sputum collection,processing, and analyses from multiple clinical sites including the needto freeze samples to conduct centralized analysis, which has thepropensity to release intracellular neutrophil elastase.High-sensitivity C-reactive protein, a marker of systemic inflammation,may have been impacted by intercurrent illnesses in this study wherepatients, though stable at randomization, had pulmonary exacerbationsthroughout the trial increasing variance and adversely influencingdetection of stable changes between groups.

This trial highlights the challenges of designing a clinical trial foran anti-inflammatory agent at the phase 2 stage of drug development. Thestudy was powered based on ppFEV₁, which required a more manageablesample size than powering such a study based on pulmonary exacerbations,even though this is a more meaningful measure of anti-inflammatory drugactivity. Future clinical trials will require adequate statisticalpowering for pulmonary exacerbation endpoints, for which a numericalsignal of benefit was seen in this trial. This poses an obviouschallenge to assess anti-inflammatory agents early in clinicaldevelopment, since biomarkers of sputum are not necessarily predictiveof intermediate term benefit. By intention, we enrolled a population atrisk for future pulmonary exacerbations which may have been a beneficialdesign feature that enabled detection of the positive trends inpulmonary exacerbations found in this study.

In summary, while there was no meaningful effect on ppFEV₁, positive andclinically relevant trends of the effect of acebilustat on rate of andtime to first pulmonary exacerbation as well as the proportion ofpatients free of pulmonary exacerbations were observed, particularly inpatients with mild disease and in those receiving concomitant CFTRmodulator therapy. In the future, the majority of people with CF areprojected to have mild lung disease (CFF Registry Report, 2017) and beon concomitant CFTR modulators. Given the importance of reducingpulmonary exacerbations in the treatment of patients with CF, furtherclinical investigation of acebilustat is warranted, focusing on thesepatient populations.

In conclusion, acebilustat is the first novel anti-inflammatory moleculeto prospectively demonstrate benefits in both reducing the frequency ofpulmonary exacerbations and prolonging time to first exacerbation, whenadded to a CF patient's existing treatment regimen in a clinical trial.Acebilustat treatment had a significant effect on reducing the rate ofpulmonary exacerbation and this effect was most notable in patients ofthe mild lung disease population (having a FEV1pp of greater than 75 atbaseline) and in patients on CFTR modulator therapy. Acebilustat-treatedpatients had a lower frequency of pulmonary exacerbations, particularlyas recruited patients had exacerbations in the year prior to study entryand therefore at high risk of new exacerbations. It was also observedthat a higher proportion of acebilustat-treated patients remainedexacerbation free during the study compared to placebo. These datasuggest that anti-inflammatory therapy effectiveness may be betterassessed using clinical events such as pulmonary exacerbations.Pulmonary exacerbations, which are a clinical marker of unbridled lunginflammation, are significant events leading to acute decompensation andchronic decline of lung function and are strongly related to reducedsurvival. Given this, acebilustat has the potential to protect patientsfrom the progressive and irreversible damage that is associated with CF.

TABLE 2 Inclusion and Exclusion criteria Inclusion criteria 18 to 30years of age inclusive at the time of screening Documented, confirmeddiagnosis of pulmonary CF (defined as follows): CF signs and symptomsAND either two CFTR mutations on genetic testing OR sweat chloride ≥60mEq/L At least one pulmonary exacerbation, based on the investigator'sjudgment, in the 12 months before screening On a stable regimen of CFtreatments with no change for at least 14 days before screening andbetween screening and baseline If on ivacaftor or ivacaftor-lumacaftorcombination, on a stable regimen for at least 8 weeks before baselineFEV₁pp ≥50 at screening Able to perform spirometry according to EuropeanRespirator Society/American Thoracic Society guidance Exclusion criteriaIn the opinion of the investigator, any significant clinical/laboratory/radiological/spirometric sign of unstable or unexpectedly deterioratingrespiratory disease within 14 days before screening or between screeningand baseline (these clinical/laboratory/ radiological/spirometric signsinclude, but are not limited to, features suggestive of a pulmonaryexacerbation as suggested by the modified Fuchs' criteria) Colonizationwith organisms associated with a more rapid decline in respiratoryfunction in CF patients (e.g. all Burkholderia species, Mycobacteriumabscessus); patients with a history of a positive culture could beconsidered free of colonization if she/he has had six subsequentrespiratory tract cultures negative for these bacteria within the past24 months prior to screening, with one of these cultures obtained within6 months prior to screening Use of systemic corticosteroids, or systemicantimicrobial therapy (other than chronic antimicrobial use, e.g.azithromycin, flucloxacillin, itraconazole) within 14 days beforescreening or between screening and baseline Regular use (>3 times perweek) of a high-dose NSAID (e.g. >1.6 g ibuprofen/day) within 60 daysbefore screening or between screening and baselineCF, cystic fibrosis; CFTR, cystic fibrosis transmembrane conductanceregulator; FEV₁pp, forced expiratory volume in 1 second percentpredicted; NSAID, non-steroidal anti-inflammatory drug; ULN, upper limitof normal.

TABLE 3 Primary and secondary endpoints Primary endpoints Absolutechange from baseline to Week 48 in FEV₁pp Safety and tolerabilitySecondary endpoints Number of pulmonary exacerbations Time to firstpulmonary exacerbation Biomarker levels (sputum DNA and elastase, serumhs-CRP) Exploratory endpoints Sputum bacterial density (total and thatof P. aeruginosa, Burkholderia cepacia complex, Achromobacterxylosoxidans, Stenotrophomonas maltophilia, and Staphylococcus aureus[including methicillin-resistant S. aureus and small colony variants ofS. aureus]) Change from baseline in health-related quality of life asmeasured by the CFQ-R

CFQ-R, Cystic Fibrosis Questionnaire—Revised; CFU, colony-forming unit;FEF₂₅₋₇₅%, forced expiratory flow during the middle portion of theforced vital capacity; FEV₁pp, forced expiratory volume in 1 secondpercent predicted; FVCpp, forced vital capacity percent predicted;hs-CRP, serum high-sensitivity C-reactive protein.

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While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

The patent and scientific literature referred to herein establishes theknowledge that is available to those with skill in the art. All UnitedStates patents and published or unpublished United States patentapplications cited herein are incorporated by reference. All publishedforeign patents and patent applications cited herein are herebyincorporated by reference. All other published references, documents,manuscripts and scientific literature cited herein are herebyincorporated by reference. The relevant teachings of all patents,published applications and references cited herein are incorporated byreference in their entirety.

1. A method of treating cystic fibrosis in a patient in need thereofand/or reducing pulmonary exacerbations in a cystic fibrosis patient,wherein the patient has a FEV₁pp greater than or equal to about 65% atbaseline, the method comprising orally administering to the patientacebilustat at a total daily dose of about 100 mg or less. 2-29.(canceled)
 30. A method of reducing the number or frequency of pulmonaryexacerbations in a patient in need thereof comprising orallyadministering to the patient acebilustat at a total daily dose of about100 mg or less. 31-59. (canceled)
 60. A method of treating cysticfibrosis in a patient in need thereof comprising orally administering tothe patient acebilustat at a total daily dose of about 100 mg or less,wherein pulmonary inflammation is reduced but the risk of pulmonaryinfection is not increased. 61-75. (canceled)
 76. A method of treatingcystic fibrosis in a patient in need thereof and/or reducing pulmonaryexacerbations in a cystic fibrosis patient, wherein the patient isundergoing concomitant treatment with a CFTR modulator, the methodcomprising orally administering to the patient acebilustat at a totaldaily dose of about 100 mg or less.
 77. The method of claim 76, whereinacebilustat is administered at a total daily dose of about 100 mg. 78.The method of claim 77, wherein acebilustat is administered at a totaldaily dose of about 50 mg.
 79. The method of claim 76, wherein the CFTRmodulator is a CFTR potentiator and/or a CFTR corrector.
 80. The methodof claim 79, wherein the CFTR modulator is a CFTR potentiator.
 81. Themethod of claim 79, wherein the CFTR modulator is a CFTR corrector. 82.The method of claim 76, wherein the patient is undergoing concomitanttreatment with at least two CFTR correctors, or at least one CFTRcorrector and at least one CFTR potentiator.
 83. The method of claim 79,wherein the CFTR potentiator is ivacaftor.
 84. The method of claim 79,wherein the CFTR corrector is lumacaftor or tezacaftor.
 85. (canceled)86. The method of claim 76, wherein the patient has an FEV1pp greaterthan or equal to about 68% at baseline.
 87. The method of claim 86,wherein the patient has an FEV1pp greater than or equal to about 70% atbaseline.
 88. The method of claim 87, wherein the patient has an FEV1ppgreater than or equal to about 75% at baseline.
 89. (canceled)
 90. Themethod of claim 76, wherein the patient experiences a decrease in therate, number, or frequency of pulmonary exacerbations in the twelvemonth period after initiating treatment with acebilustat.
 91. The methodof claim 90, wherein the patient does not experience a pulmonaryexacerbation for at least forty-eight weeks after initiating treatmentwith acebilustat.
 92. The method of claim 76, wherein the patientexperiences a decreased number of pulmonary exacerbations in the twelvemonth period after initiating treatment with acebilustat as compared tothe number of pulmonary exacerbations in the twelve month period priorto initiating treatment with acebilustat.